I have just bought a diesel x-line webasto 9kw heater with frost stat (for winter) and when testing it out back home it seems the coldest it runs on hot water is 26C, it's that hot I cant even hold my hand under the brush head.... I'm concerned I am going to crack glass in summer running that temp let alone in winter. What do the hot water users run there temperatures at during summer and winter months please? Obviously it'll cool down much more through the pipes in the winter month but turning it up isn't a problem. Maybe this is normal and it's fine to clean glass with minimal risk. Any advise would be great fully appreciated ?