Heat only > combi - what should I be aware of

JPE23 · Post by **JPE23** » Sat Oct 19, 2024 3:28 pm

Moving from a heat only to a combi PRIMARILY for space saving reasons (I know all of the arguments). My house is a large 3bed semi with 9 rads.

Just deciding what key things to look out for in choosing a good combi.

JPE23 · Post by **JPE23** » Mon Oct 21, 2024 7:26 am

Bump!

gas4you · Post by **gas4you** » Tue Oct 29, 2024 6:32 pm

Size a combi for the water flow you have and need. You may also need the gas pipe from the meter made bigger.

ericmark · Post by **ericmark** » Fri Nov 01, 2024 9:39 am

I found mother's combi boiler has two options, eco on and eco off, with eco off there is a small reservoir of hot water, so quick to get hot water to taps, and also one can run the taps slowly with just a dribble of hot water, but using shower it went from cold to hot then back to cold as the reservoir ran out, and finally back to hot.

With eco on shower worked OK but taps either full on or off, reduce output at taps and no hot water.

My house was before the combi two independent gas boilers, and the DHW one a main seven was around 18 kW output, delay getting hot water, but worked well, filling a bath was slow, but really other than that did not really notice the change. Big problem with a combi is if it is too big, the minimum output is important.