Hot water system

[Pane]

A bit of a hypo mix would also help to kill off all that slimy algae and brighten up the white work as well ?

As would de greaser or Tfr.

 

[Pane]

I use hot water most of the time and like a challenge like the con roof it’s great when you have finished and stand back and give yourself a well done .Roofs like that one you charge accordingly and explain why it is costing so much and when the customer sees the results they are over the moon and I get a lot of recommendations through it .Yes hard work but golden rewards which is what you want

@Clean zero. I dont mind Conservatories like that, as long as not stupidly awkward..
Making a noticeable difference, well worth it!. Charge accordingly.

 

[Pjj]

As would de greaser or Tfr.

TFR and degreasers don’t kill off the spores behind brackets etc hypo does and turns it to slime it reduces the amount of scrubbing dramatically and speeds up the job time .

 

[TimsScrims]

We do 4 weekly cleans on the coast that the glass is opaque after 4 weeks seagull poo sticks like glue it cuts the time in less than half using hot in this type of work .it’s not cheap I accept but it’s still cost effective .

I know this is an old post but I've finally had my webasto hot water unit fixed and is purring like a cat. ive got the vitron charger installed which is awesome charging my battery, but what I want to know is, do you think I can get away with just using my primary battery (115Ah) which powers my power reel and pump, to keep my hot water unit going for a 7 hour day?
Or do you think I need to daisy chain a secondary 115Ah battery? How do you have your battery system setup for hot water?

Thanks appreciate it.

 

[Pjj]

I know this is an old post but I've finally had my webasto hot water unit fixed and is purring like a cat. ive got the vitron charger installed which is awesome charging my battery, but what I want to know is, do you think I can get away with just using my primary battery (115Ah) which powers my power reel and pump, to keep my hot water unit going for a 7 hour day?
Or do you think I need to daisy chain a secondary 115Ah battery? How do you have your battery system setup for hot water?

Thanks appreciate it.

@spruce is the technical guy and will explain it far better than me but don’t think that would be enough amp hours I think you would be draining the battery to much

 

[spruce]

I know this is an old post but I've finally had my webasto hot water unit fixed and is purring like a cat. ive got the vitron charger installed which is awesome charging my battery, but what I want to know is, do you think I can get away with just using my primary battery (115Ah) which powers my power reel and pump, to keep my hot water unit going for a 7 hour day?
Or do you think I need to daisy chain a secondary 115Ah battery? How do you have your battery system setup for hot water?

Thanks appreciate it.

This is one of those "how long is a piece of string" questions which depends on so many factors.

I tend to do what a supplier recommends as their experience is better than mine. If Grippatank were supplying a diesel heater and electric reel, they will supply 2 Numax combo leisure batteries and link them together. The combo battery has CCA rating.

I believe that the controller made by Spring Europe fitted to the p/f reel will dampen the initial milliseconds short when starting the electric reel. Maybe Ian Sheppard of Spring could add his input. It's this high DC current draw that I would be concerned about with my heater. @Ian Sheppard

What we do know is that @dazmond has been running a 9.1kw diesel heater supplied by Grippatank, a Purefreedom electric reel and his pump successfully for many years with 2 x Numax leisure batteries, a b2b on board charger and a top up charge every night to fully recharge his batteries.

 

[TimsScrims]

This is one of those "how long is a piece of string" questions which depends on so many factors.

I tend to do what a supplier recommends as their experience is better than mine. If Grippatank were supplying a diesel heater and electric reel, they will supply 2 Numax combo leisure batteries and link them together. The combo battery has CCA rating.

I believe that the controller made by Spring Europe fitted to the p/f reel will dampen the initial milliseconds short when starting the electric reel. Maybe Ian Sheppard of Spring could add his input. It's this high DC current draw that I would be concerned about with my heater. @Ian Sheppard

What we do know is that @dazmond has been running a 9.1kw diesel heater supplied by Grippatank, a Purefreedom electric reel and his pump successfully for many years with 2 x Numax leisure batteries, a b2b on board charger and a top up charge every night to fully recharge his batteries.

Yeah i agree every system is different. Ive migrated to the pure freedom hot water elec reelmaster, fixed ontop of my 500L cube tank.

Ive daisy chained my original 2 leisure batterys that xline fitted (both same manufacturer and volts) so my vitron charger positive cable (which is fused) goes straight to my heater battery, then short positive and negative cables attached to the battery that powers my pump and reel, that same battery is earthed to the van wall.
This was all down to google research, ive tested it on my driveway it seems to work fine, but the real test will be when i do a full day cleaning next week.

despite having a good b2b charger using thick 16mm 110amp cabling, im still going to hard charge at least my heater battery fairly regularly, especially in the winter months, as the cold canes the battery and more times than not, because the cold has depleted my heater battery sitting on the drive the frost stat doesnt work so doesnt protect my hoses. All fun and games. I want to make sure frost stat is gonna work on those frosty nights so i dont wake up to frozen hozes & pump - which means hard charging battery overnight (common sense tells me anyway)

One thing which has stumped me a bit though…my 5kw xline hot water unit which was fitted in may 2020 (used roughly about 18 months part time before the thermo top evo broke) xline guys put in lime antifreeze, they told me to not let it go below half way, then i bought prestone premixed (50/50) topped it up same year, a further several months later and the coolant level never went down. If it doesnt need to be topped up regularly, then how do u change the coolant round for fresh antifreeze if its been in the unit/resevoir for years.
I dont know whether im barking up the wrong tree, but ive been testing my now fixed hot water unit for past day or so now, checking temperatures, cleaning my own windows etc, and it can be random temperatures. One minute its tepid, next its hot, then next it goes down to lightly warm…is this something to do with my antifreeze thats been in there for 3 or so years? Ive looked inside and the coolant looks clean.

Then stupidly i went to my v11 controller to the temp (frost stat temp cage dangling externally off my tank cage) to see if i can change the temp of the water from the controller, it was reading 10c then as day went on went to 16c then dawned on me that it was the temp of the back of the van lol! Changing temp from the controller would just be too logical and easy after all!
The only way i can change the temperature of my water on the xline webasto unit is the temp gauge on the unit itself which is annoying, but even adjusting that periodically didnt overly make much difference, even when adjusted to ‘high’.
So would this issue be ‘old’ coolant? Or is this normal? Even on ‘high’ setting ive struggled to get over 40c when my unit should be able to get well over that.

Btw i tested the water for about an hour at home.
I just dont know why after 5-10 mins of startin the heater goin to toasty then shortly after goin to tepid or lower.

 

[spruce]

Years back I made up a test bed using a Webasto Thermotop 5.2kw boiler.

I can't remember the figures but the most I could get out of the brush head with a fully coiled up hose on the reel was 35 degrees. The cold water temperature was 9 degrees. I could have turned my water flow down which may have increased the heat to the brush, but I didn't carry on with the experiment.

I couldn't figure that out as the formula suggested to this heater should be able to heat the water for 2 of us to that temperature.

Then I realised that a large portion of heat produced by the boiler goes out of the exhaust as wasted heat. That 5.2kw figure includes that heat. My calculation was that the heater was at best only 45% efficient, probably less in reality.

We have thermo mixing valves on our heat exchangers. With a 9.1kw boiler we can get a maximum of 50 degrees each of water temperature leaving the boiler.

If I want more my lad gets less. If it's cold outside and a long length of house is lying on frozen ground, then the water leaving the brush head is tepid.
We are using hot water to make life easier for us. Our hoses remaining supple is the main reason and a major benefit in winter.

I very much doubt your antifreeze is an issue. All it does is to stop the water freezing in the system. But just because you have anti freeze doesn't mean the whole system is protected. Pure water on the 'other side' of the heat exchanger hasn't got any antifreeze in it so will freeze. Hence the reason for a working froststat even if using a oil filled radiator in the back.

 

[dazmond]

Yeah i agree every system is different. Ive migrated to the pure freedom hot water elec reelmaster, fixed ontop of my 500L cube tank.

Ive daisy chained my original 2 leisure batterys that xline fitted (both same manufacturer and volts) so my vitron charger positive cable (which is fused) goes straight to my heater battery, then short positive and negative cables attached to the battery that powers my pump and reel, that same battery is earthed to the van wall.
This was all down to google research, ive tested it on my driveway it seems to work fine, but the real test will be when i do a full day cleaning next week.

despite having a good b2b charger using thick 16mm 110amp cabling, im still going to hard charge at least my heater battery fairly regularly, especially in the winter months, as the cold canes the battery and more times than not, because the cold has depleted my heater battery sitting on the drive the frost stat doesnt work so doesnt protect my hoses. All fun and games. I want to make sure frost stat is gonna work on those frosty nights so i dont wake up to frozen hozes & pump - which means hard charging battery overnight (common sense tells me anyway)

One thing which has stumped me a bit though…my 5kw xline hot water unit which was fitted in may 2020 (used roughly about 18 months part time before the thermo top evo broke) xline guys put in lime antifreeze, they told me to not let it go below half way, then i bought prestone premixed (50/50) topped it up same year, a further several months later and the coolant level never went down. If it doesnt need to be topped up regularly, then how do u change the coolant round for fresh antifreeze if its been in the unit/resevoir for years.
I dont know whether im barking up the wrong tree, but ive been testing my now fixed hot water unit for past day or so now, checking temperatures, cleaning my own windows etc, and it can be random temperatures. One minute its tepid, next its hot, then next it goes down to lightly warm…is this something to do with my antifreeze thats been in there for 3 or so years? Ive looked inside and the coolant looks clean.

Then stupidly i went to my v11 controller to the temp (frost stat temp cage dangling externally off my tank cage) to see if i can change the temp of the water from the controller, it was reading 10c then as day went on went to 16c then dawned on me that it was the temp of the back of the van lol! Changing temp from the controller would just be too logical and easy after all!
The only way i can change the temperature of my water on the xline webasto unit is the temp gauge on the unit itself which is annoying, but even adjusting that periodically didnt overly make much difference, even when adjusted to ‘high’.
So would this issue be ‘old’ coolant? Or is this normal? Even on ‘high’ setting ive struggled to get over 40c when my unit should be able to get well over that.

Btw i tested the water for about an hour at home.
I just dont know why after 5-10 mins of startin the heater goin to toasty then shortly after goin to tepid or lower.

I used my wet and dry vac and sucked all the anti freeze out of my header tank and replaced with fresh earlier this year

 

[spruce]

I used my wet and dry vac and sucked all the anti freeze out of my header tank and replaced with fresh earlier this year

Good idea. Less messy than removing the hose from the heater inlet.

 

[ched999uk]

Antifreeze wont effect the temp out of the heater. It's just there to stop the coolant freezing and to prevent corrosion of the internals of the heater and pipework.
As for the temp going up and down that could be due to it shutting down and then restarting between jobs. Some systems have bypasses in so when you shut off your pole the heater continues to heat water and puts it back in your tank, therefore never shutting down. Other people plug their hose back into the tank so again the heater is still heating the water. I don't think these heaters like switching on and off frequently as startup tends to use a bit more diesel and can, over time, clog the combustion chamber with excess carbon, plus startup pulls a lot more amps than when it's fully running.

Just so you know, when you parallel up the batteries any current you pull comes out of both batteries i.e. if they are physically connected +ve to +ve and -ve to -ve then it's effectively 1 battery. The wires connecting between the 2 batteries should be the same thickness as your b2b and have a fuse in.

Definitely mains charge your batteries each night to ensure they last as long as possible.

 

[Limbo_117]

Glycol coolant has a lower heat capacity than pure water, so may be why you're experiencing lower temperatures through the heat exchanger. Many use glycol for its antifreeze properties.

 

[spruce]

Antifreeze wont effect the temp out of the heater. It's just there to stop the coolant freezing and to prevent corrosion of the internals of the heater and pipework.
As for the temp going up and down that could be due to it shutting down and then restarting between jobs. Some systems have bypasses in so when you shut off your pole the heater continues to heat water and puts it back in your tank, therefore never shutting down. Other people plug their hose back into the tank so again the heater is still heating the water. I don't think these heaters like switching on and off frequently as startup tends to use a bit more diesel and can, over time, clog the combustion chamber with excess carbon, plus startup pulls a lot more amps than when it's fully running.

Just so you know, when you parallel up the batteries any current you pull comes out of both batteries i.e. if they are physically connected +ve to +ve and -ve to -ve then it's effectively 1 battery. The wires connecting between the 2 batteries should be the same thickness as your b2b and have a fuse in.

Definitely mains charge your batteries each night to ensure they last as long as possible.

This is possibility number 1 of the heater shutting down and then restarting as you say.

The other possibility is @TimsScrims using a high flow rate. If his cold water is zapping the heat faster than his boiler can produce it, then his water temperature to his brush head is going to get lower.

The suppliers also recommend starting the heater before starting work, so the water is hot to begin with. If I start my heater as the 2 of us are working, it takes ages before the internal water circuit gets up to temperature.

If our thermo mixer valve is set at 50 degrees and the internal heating circuit has only reached 40 degrees, the water going to the brush head is going to zap every scrap of heat as it wants to achieve the water temperature of 50 degrees. But if the internal water circuit is 60 degrees, then the mixer valve is going to introduce some cold into the mix to reduce the temperature to 50 degrees. The demand on the boiler becomes less.

The trade referred to these 5.2kw heaters as cabby heaters. They were designed to heat a freezing cold engine to engine operating temperature. However, these heaters could also be used to trigger the vehicle's internal blower to warm the cabin and defrost the windscreen. The operating timer would usually be set to 30 minutes and then the heater would switch off. If the internal defroster was set, then the heater would never get that hot. We have adapted the heater for a different use it wasn't designed for, so we have to work around that design.

I have added a third heat exchanger to my diesel heater. It is linked to a third Shurflo pump via a 12v temperature controller. Once the internal hot water circuit reaches 83 degrees, this controller kicks the third pump on and bleeds the heat back down to 79 degrees. This keeps the heater from powering down and on reduced heat mode. So I can talk for hours without having to return to the van.

 

[Limbo_117]

As has been said, the main issue with these heaters is once the heating loop is up to temperature, then the unit will shut down.
Power up / down pulls apx. 17 amps so if allowed to repeat through the day your battery will suffer.
This is the unit burning off any excess fuel in the ignition chamber.

Main concern is to prevent this.

I built my own system (9kw webchinasto) I use a third heat exchanger (HE) to bleed heat into the tank once the loop is hitting 85°c, so stops this cycle.
I also fitted an EGR cooler from a Jaguar on the exhaust. Before fitting exhaust was 300°c +
After fitting, 70°c
Tank water is circulated through the EGR
I've had no issues with the heater, but have to run the coolant loop heat higher as the heat exchangers are slightly undersized (due space restrictions and my inexperience with calculating temperature exchange deltas)

Another reason for high temp is that the header tank is only 5 liters which is the biggest I can get that is made from polypropylene which can take 120°c

All the header tanks I see on xline, pure freedom etc. use a tank manufactured by kingfisher (polyethylene) which can take 60°c.
I Have seen these melt if the heater loop is turned up too much.

Another (simpler way) to bleed heat back to tank is a simple solenoid valve between the HE & hose reel. But the pump on this line must be switched on.

 

[kevinc250]

As has been said, the main issue with these heaters is once the heating loop is up to temperature, then the unit will shut down.
Power up / down pulls apx. 17 amps so if allowed to repeat through the day your battery will suffer.
This is the unit burning off any excess fuel in the ignition chamber.

Main concern is to prevent this.

I built my own system (9kw webchinasto) I use a third heat exchanger (HE) to bleed heat into the tank once the loop is hitting 85°c, so stops this cycle.
I also fitted an EGR cooler from a Jaguar on the exhaust. Before fitting exhaust was 300°c +
After fitting, 70°c
Tank water is circulated through the EGR
I've had no issues with the heater, but have to run the coolant loop heat higher as the heat exchangers are slightly undersized (due space restrictions and my inexperience with calculating temperature exchange deltas)

Another reason for high temp is that the header tank is only 5 liters which is the biggest I can get that is made from polypropylene which can take 120°c

All the header tanks I see on xline, pure freedom etc. use a tank manufactured by kingfisher (polyethylene) which can take 60°c.
I Have seen these melt if the heater loop is turned up too much.

Another (simpler way) to bleed heat back to tank is a simple solenoid valve between the HE & hose reel. But the pump on this line must be switched on.

ahh, someone else who has harnessed the heat from the exhaust, congratualtions, it seems people like yourself now find that you can get extra heat from that, it won't be long before the manufactuers will be clicking onto this.

 

[spruce]

As has been said, the main issue with these heaters is once the heating loop is up to temperature, then the unit will shut down.
Power up / down pulls apx. 17 amps so if allowed to repeat through the day your battery will suffer.
This is the unit burning off any excess fuel in the ignition chamber.

Main concern is to prevent this.

I built my own system (9kw webchinasto) I use a third heat exchanger (HE) to bleed heat into the tank once the loop is hitting 85°c, so stops this cycle.
I also fitted an EGR cooler from a Jaguar on the exhaust. Before fitting exhaust was 300°c +
After fitting, 70°c
Tank water is circulated through the EGR
I've had no issues with the heater, but have to run the coolant loop heat higher as the heat exchangers are slightly undersized (due space restrictions and my inexperience with calculating temperature exchange deltas)

Another reason for high temp is that the header tank is only 5 liters which is the biggest I can get that is made from polypropylene which can take 120°c

All the header tanks I see on xline, pure freedom etc. use a tank manufactured by kingfisher (polyethylene) which can take 60°c.
I Have seen these melt if the heater loop is turned up too much.

Another (simpler way) to bleed heat back to tank is a simple solenoid valve between the HE & hose reel. But the pump on this line must be switched on.

My third heat exchanger is a 22kw unit. Works fine. I also have the pump on a 12v PWM regulator. The pump speed is set so the pump pushes just enough hot water to lower the temp slowly.
I've had no issues using the same plastic header tank all the suppliers use.

 

[Pjj]

I used my wet and dry vac and sucked all the anti freeze out of my header tank and replaced with fresh earlier this year

That’s quite a good idea I generally take a hose off and drain it into a bucket , but might try the vac

 

[Pjj]

Antifreeze wont effect the temp out of the heater. It's just there to stop the coolant freezing and to prevent corrosion of the internals of the heater and pipework.
As for the temp going up and down that could be due to it shutting down and then restarting between jobs. Some systems have bypasses in so when you shut off your pole the heater continues to heat water and puts it back in your tank, therefore never shutting down. Other people plug their hose back into the tank so again the heater is still heating the water. I don't think these heaters like switching on and off frequently as startup tends to use a bit more diesel and can, over time, clog the combustion chamber with excess carbon, plus startup pulls a lot more amps than when it's fully running.

Just so you know, when you parallel up the batteries any current you pull comes out of both batteries i.e. if they are physically connected +ve to +ve and -ve to -ve then it's effectively 1 battery. The wires connecting between the 2 batteries should be the same thickness as your b2b and have a fuse in.

Definitely mains charge your batteries each night to ensure they last as long as possible.

Oliver at Grippatank told me if you use 100% antifreeze in the header tank that it will increase the water temperature quite dramatically and it could damage the heat exchangers I can’t quite remember the full explanation but he said use a 50-50 antifreeze and water mix that’s what I have always done .

 

[Pjj]

As has been said, the main issue with these heaters is once the heating loop is up to temperature, then the unit will shut down.
Power up / down pulls apx. 17 amps so if allowed to repeat through the day your battery will suffer.
This is the unit burning off any excess fuel in the ignition chamber.

Main concern is to prevent this.

I built my own system (9kw webchinasto) I use a third heat exchanger (HE) to bleed heat into the tank once the loop is hitting 85°c, so stops this cycle.
I also fitted an EGR cooler from a Jaguar on the exhaust. Before fitting exhaust was 300°c +
After fitting, 70°c
Tank water is circulated through the EGR
I've had no issues with the heater, but have to run the coolant loop heat higher as the heat exchangers are slightly undersized (due space restrictions and my inexperience with calculating temperature exchange deltas)

Another reason for high temp is that the header tank is only 5 liters which is the biggest I can get that is made from polypropylene which can take 120°c

All the header tanks I see on xline, pure freedom etc. use a tank manufactured by kingfisher (polyethylene) which can take 60°c.
I Have seen these melt if the heater loop is turned up too much.

Another (simpler way) to bleed heat back to tank is a simple solenoid valve between the HE & hose reel. But the pump on this line must be switched on.

My header tank holds around 10 ltr depending how high you fill it I keep it 3/4 full

 

[TimsScrims]

This is possibility number 1 of the heater shutting down and then restarting as you say.

The other possibility is @TimsScrims using a high flow rate. If his cold water is zapping the heat faster than his boiler can produce it, then his water temperature to his brush head is going to get lower.

The suppliers also recommend starting the heater before starting work, so the water is hot to begin with. If I start my heater as the 2 of us are working, it takes ages before the internal water circuit gets up to temperature.

If our thermo mixer valve is set at 50 degrees and the internal heating circuit has only reached 40 degrees, the water going to the brush head is going to zap every scrap of heat as it wants to achieve the water temperature of 50 degrees. But if the internal water circuit is 60 degrees, then the mixer valve is going to introduce some cold into the mix to reduce the temperature to 50 degrees. The demand on the boiler becomes less.

The trade referred to these 5.2kw heaters as cabby heaters. They were designed to heat a freezing cold engine to engine operating temperature. However, these heaters could also be used to trigger the vehicle's internal blower to warm the cabin and defrost the windscreen. The operating timer would usually be set to 30 minutes and then the heater would switch off. If the internal defroster was set, then the heater would never get that hot. We have adapted the heater for a different use it wasn't designed for, so we have to work around that design.

I have added a third heat exchanger to my diesel heater. It is linked to a third Shurflo pump via a 12v temperature controller. Once the internal hot water circuit reaches 83 degrees, this controller kicks the third pump on and bleeds the heat back down to 79 degrees. This keeps the heater from powering down and on reduced heat mode. So I can talk for hours without having to return to the van.

Yes you are right, I did notice (as I like to work at a very high flow rate 90-99) the heat doesn't go up as high as I would like, but when flow rate is down to say around 45 or less it seems to come out warmer/hotter, this makes sense as water isn't rushed out the heater system, no offence to people who do work on that flow but its just not for me.

Yes I wouldnt turn my controller on as I start my first job. now ive got hot water again, id turn it on before leaving for work (most my work is on my doorstep, can be a good and bad thing), so need to get in routine of turning it on just before leaving the house.

Also id agree with you about the hoses in the winter time, they get so bristle and running along frosty/icy pavements was never good, so even keeping the hoses tepid/warm is definitely the way to go, no matter what anyone says, window cleaning equipment does not like cold temperatures, poles/pumps/hoses/connector fittings EVERYTHING, I constantly had problems with something or other when temperatures ran 2/3c or below, things used to snap/break/freeze was a complete headache. Hot water or even 'warm water' eliminates all that. The investment pays back over time to be able to work consistently over the Scottish Highland 5 month winter.
But also, hot water is also very useful in the summer (which I wish I had working then) the bird muck has been unbelievable this year and slowed me down something rotten. Hot water isnt just for Christmas, its year round.

Im now trying to convince my brother to invest in hot water as he works on west coast of cumbria, so lots of sea air, gulls etc. Unconvinced even when I say it should speed him up.

What is the ideal temperature to work with from the brush head? I've heard 40c quite a bit.

 

[spruce]

Yes you are right, I did notice (as I like to work at a very high flow rate 90-99) the heat doesn't go up as high as I would like, but when flow rate is down to say around 45 or less it seems to come out warmer/hotter, this makes sense as water isn't rushed out the heater system, no offence to people who do work on that flow but its just not for me.

Yes I wouldnt turn my controller on as I start my first job. now ive got hot water again, id turn it on before leaving for work (most my work is on my doorstep, can be a good and bad thing), so need to get in routine of turning it on just before leaving the house.

Also id agree with you about the hoses in the winter time, they get so bristle and running along frosty/icy pavements was never good, so even keeping the hoses tepid/warm is definitely the way to go, no matter what anyone says, window cleaning equipment does not like cold temperatures, poles/pumps/hoses/connector fittings EVERYTHING, I constantly had problems with something or other when temperatures ran 2/3c or below, things used to snap/break/freeze was a complete headache. Hot water or even 'warm water' eliminates all that. The investment pays back over time to be able to work consistently over the Scottish Highland 5 month winter.
But also, hot water is also very useful in the summer (which I wish I had working then) the bird muck has been unbelievable this year and slowed me down something rotten. Hot water isnt just for Christmas, its year round.

Im now trying to convince my brother to invest in hot water as he works on west coast of cumbria, so lots of sea air, gulls etc. Unconvinced even when I say it should speed him up.

What is the ideal temperature to work with from the brush head? I've heard 40c quite a bit.

The other thing regarding flow is that hot water flows quicker than cold as it's viscosity changes with temperature. The hose also expands a bit when warm.

We still have a couple of old Varistream controllers on the van. I like my flow set at 4 (around 40 on Spring controllers). When the diesel heater is on, I drop that to 3 as I'm getting the same rinse rate as I do on 4 using cold.

I have also switched to fan jets. I always preferred pencil jets, but there was talk on the forums about some cleaners cracking glass with hot water. So I thought that having fan jets would spread the heat rather than it being a concentrated jet using pencils.

Squeeky Clean Dave on YouTube did a video of pouring boiling water on frozen double glazing windows without the glass cracking. That video put my mind at rest, but as I had already got used to fan jets, I stuck with them.

If I use the heater in summer, the water from the jets does feel hot to the touch when I've being running the water a while.

This is another thing. It takes a while for the heat to become noticeable at the brush head. When on compact work the heat is there all the time, but if you do one house and pack away to move to the next, the warm water in the hose quickly cools.

When I do put the heater on I generally swap the brush head to a stiff one which I don't use with cold. My go-to brush is soft to medium and I sometimes use that with hot. It hasn't deformed and the Gardiner brush guide says it's suitable for 30 degrees of water temperature. But as I say, we really use the heater in summer so the water at the brush head isn't doing too be steaming hot.

But my system is set up so the 2 of us can have hot water. Occasional my son will use the backpack which we refill using a 20 litre plastic drum. If I connect a hose up to the van port and put the pump on full to fill that container quickly, the 9.1kw boiler won't keep up with the high flow rate going through the heat exchanger.