New combi takes ages to heat the house

ColdAl

I've just had a glow worm combi 24kw to replace my old tank based 15kw. My old system would heat my home up very quickly, so much so I would turn it off again after twenty minutes. The new boiler however is leaving me feeling cold even an hour later. I notice that the room is only 0.6 to 1 degree hotter after half an hour. Why is it so noticeably slower than the old system to heat my home? There is heat getting to the radiators but even in my middle bedroom, there remains a chill after hours of being on. Likewise the temp in my living room where the stat is crawls slowly so if I'm cold at 6 I'll still be cold at 7pm. How can this be sorted as I expected the performance to be better than the old antiquated system. Big thanks

Jamie Hall

Assuming that there has been little or no change in the radiation, there are two places to begin looking — and it's not hard and they require little equipment.

Start out with a very good thermometer, preferably one which you can strap to a pipe or at the very least get into good solid contact with the pipe. IR (non-contact) thermometers can be made to work, but they require uniform pipe finish and are somewhat finicky.

Then, measure the temperature of the water being sent out to the radiation, and the temperature of the water returning.

Odds are good you will find one of two possibilities: the temperature of the water being sent to the radiation is set too low (very likely) or the difference in temperature between what is going out and what is coming back is too great (it should be around 20 degrees Fahrenjeit or 10 degees Celsius).

Now that will tell you whether the control on the new boiler for water temperature is set too low (the first case) or whether you have too little flow (if the difference is too great).

Report back, please, and we can proceed from there.

HVACNUT

Is ODR being used where it wasn't before?

neilc

aw, come on, let's ask for a distant broad view picture of the new boiler, and connected system piping, floor to ceiling, everything in one shot, or 2 from a second angle,

where are you located?