Heat pump one year stats (2023 Update)

[Theo]

You may need to replace the radiators with ones with more panels or fins, eg we went from single-panel single-convector to double-panel, some single some double-convector. A couple of them got marginally larger. We opted to replace them all so they all matched (no old 1970s radiators remaining) but we didn't need to do that according to the heat loss calcs - some of the old radiators were in bad condition so it was better to start again.

No UFH, and with a concrete slab it would have been awkward to install that.

Theo

[Steve Jones]

Thanks, I have a 1957 bungalow on a concrete slab, and am thinking of upgrading to a heat pump at some point

[Theo]

Pretty similar here (1965 bungalow, loft conversion). Cavity wall insulation, ~100mm loft insulation, it works fine.

Theo

[Vir Campestris]

Are you sure that's an upgrade?

Next time it's cold check the rad temperature, and that will give you an idea of whether a heat pump could cope.

If they're too hot to touch it won't.

Andy

[Theo]

That's not correct. The boiler will output whatever temp it feels like - if it's not a condensing boiler then it can't lower the flow temp in relation to heat demand, or it may be set too high (often 60+C). Many boilers are massively oversized for the actual heating load so they cycle.

In most traditional boiler setups the boiler will heat the rads until the thermostat or TRV shuts them off. The rads go hot when the boiler runs and then cool off when the boiler doesn't run. Touching the rad when the boiler is or isn't running is no guide to how things will work with a lower flow temp.

Theo