Huge radiators and single pipe gas boiler, heat pump work?

FreeBear

wrf12345 said: Thanks, no TRVs and the rad's are indeed in series, done at a time when there were no rules other than for the gas boiler bit (almost an antique), the radiators were designed for a house with zero insulation and single pane windows, both of which have been upgraded

By the sounds of it, the entire heating system would benefit from a redesign. A single pipe system is not efficient, and comes with a whole host of problems. Putting in a twin pipe system gives you the opportunity to rationalise the pipe routing and radiator location - In my opinion, there is no need to site radiators under windows in a well insulated & draught free property. So radiators can be mounted on internal walls where you don't have height restrictions (so taller radiators if needed). Pipework and radiators can also be suitably sized for a heat pump (32/28/22mm for feed & return and 15mm to the radiators) even if you go for a conventional gas/oil boiler.

Replumbed my heating system last year, rerouting pipework, using 22mm pipe for the feed/return, and oversizing the radiators. Still fitted a gas boiler as the BUS grant was only £5000 and I would have had to spend a lot on insulation upgrades. With the grant now at £7500 and relaxation of the insulation rules, I would have gone for a heat pump. That is still an option up until 2028 (maybe longer if the end date is extended), and most of the plumbing is already in place.