More on boilers

[Andrew Welham]

Dear all

Starting to get really confused I was under the impression that now or I the near future both

Thermostatic radiator valves And Condensing boilers

Would be a prerequisite for a new installation.

Reading some details in FAQ the two systems don?t seem to be entirely compatible. The reason being that thermostatic radiator valves mean the water temperature returning the boiler is higher than the optimum?

Andrew

[BillV]

Thermostatic rad valve or some other method of controlling the room temp, e.g. thermostat, is required now in every room, new build or refurb. You don't really have to do this. Fitters like to have TRVs in every room because it makes it easier for them as they don't usually bother balancing the rads properly. Condensing boilers will be required soon. When that happens you won't be able to buy otherwise.

Modern boilers are able to modulate their power to fit the load so your last statement doesn't apply. Bear in mind that a condensor will probably not operate at full efficiency except on the coldest days. Also with a condensor you will need those higher output rads because the input temperature to the rads will be lower.

[IMM]

Not quite. Load compensation control on most condensers will take care of rads designed to run at 80C. Once up to temp the boiler drops the temperature flow temperature to the buildings heating load.

[Andrew Welham]

Thanks for the answers I will fit TRVs to all the rads except the bathroom

Any comments on the boiler types specified or the rads i an considering full detials can be found in the post "Combies , corgo gas fitters, rads and stuff"

Andrew

[IMM]

You will need a boiler "interlock". You need to have a stat or flowswitch to detect when the house is up to temp and the boiler is switched off. Best put a stat in the hall and no TRV there.