AncientMariner said:

The situation is not helped by it being a large diameter pipe system and cast iron radiators, likely original from when the Class II listed building was built very early 1900s.  (Some of the joints appear to be caulked lead!)

You appear to be describing a central heating system that may have used solid fuel, either coke or coal in a boiler that could have raised a good head of steam?

broadgage said:

This was cured by the addition of fine iron fillings to the water which was stirred around. This promptly reduced the leakage as the iron filings blocked up the holes, after a few days leakage was eliminated as the iron filings rusted and expanded.

Drifting even further away - presumably Bar's Leaks is similar. I always worry that it could be Blocks Radiators.

Electricity is 24.847p per kWh

Depending on the pattern of heating demand, it might be possible to get a better price than that. I know the old E7/E10 tariffs aren't often offered to new customers these days, but several suppliers are now offering "heat pump tariffs" with usually significantly lower unit prices for a fair chunk of the of the day (deals vary but something in the region of 10-11p/kWh for a total of 7 - 8 hrs/day usually in two or three slots, early morning, early afternoon and late evening). That's not to say you can only run the HP during those hours, but it can bring the average unit cost down quite a bit, especially when it's not quite so cold you can  weight the running times to the cheaper periods. Also if there's no other gas appliances, discontinuing the gas supply should save you the standing charge - which probably isn't huge, but adds up.

I agree 100kW sounds huge - you could probably heat 10-30 houses with that.

   - Andy.

AJJewsbury said:

I agree 100kW sounds huge - you could probably heat 10-30 houses with that.

Modest well-insulated ones!

If you heat the house in the morning until shortly before the household departs for work or school; and again from home time until bed time, you need enough to heat up the environment. That does not mean an average output of 100 kW, which is why I asked about the use of the building.

Thank you all for your comments, much appreciated.

Chris Pearson

I agree regarding the existing radiators and for that matter the radiating pipework. The thoughts of 10 off 3 kW heat pumps is 8 or 9 too many for me. 

Good comment re it being only 20 years old. 

It is a https://idealcommercialboilers.com/uploads/documents/Installation-Concord-CXA-40H-120H-Installation-Guide-157290.pdf  which is Open Vented, Conventional Flue, No Modulation – All or Nothing. The heat exchanger is cast iron. Over the last 3 years or so, both circuit boards have been replaced – a long time intermittent issue, also probes etc. The only thing original is the gas valve.

Hot water is from a 3-phase 27kW flow heater. A Steibel Eltron as suggested by Mike mapj1 and very well it works too. Thanks Mike

Gas is only for space heating during cold months.

The building is in use most days, there are three zones which helps.  However the building is slow to warm up.

Alanblaby

Air to air sounds interesting, BUT anything external is a nightmare when dealing with the Council’s Conservation Officer. Roof mounting would also be out – too high.

mapj1

The only south facing roof area is at the front adjacent the road. The current boiler does not modulate – just all or nothing. The heat exchanger is cast iron. Over the last 3 years or so, both circuit boards have been replaced – a long time intermittent issue, also probes etc. The only thing original is the gas valve.

Solid brick walls, typical pitched ceiling, no insulation, single glazed. I haven’t got the stamina to convince the Council’s Conservation Officer. Problem is, they seem to be on short contracts, so you can speak but can be difficult getting it on paper. Last time I tried they would not accept my scale drawing of a plan showing a new cast iron soil pipe on the rear wall (to fit an upstairs bathroom in the old attached caretakers house) so had to obtain a professional drawing………

The photo currently on ebay (???) shows the building quite well – it is both buildings:  https://www.ebay.co.uk/itm/275340456782

Also https://hawardeninstitute.org.uk/

burn

Yes, original boiler was coke fired down in the cellar. Which is where the gas boiler is now. I don’t know what the rating of the coke fired boiler was, I seem to remember the primary school I attended had a coke fired CH boiler back in the 50s.  Coke was readily available from the local steelworks in Shotton, Flintshire.

Here are a couple of photos taken this morning showing the cellar pipework adjacent to the boiler

https://ancient-mariner.co.uk/public/20241114_Gas%20Boiler%201.jpg

https://ancient-mariner.co.uk/public/20241114_Gas%20Boiler%202.jpg

The white pipe is from a sump pump and the two cast iron(?) pipes head off underground beneath a courtyard to the gymnasium.

Cheers!

Clive

AncientMariner said:

Good comment re it being only 20 years old.

AncientMariner said:

Over the last 3 years or so, both circuit boards have been replaced – a long time intermittent issue, also probes etc. The only thing original is the gas valve.

Clive, thank you for the further info. "Village hall" is perhaps misleading. :-)

Possibly still more reliable than a modern boiler.

My CX170 (i.e. 170 Btu/hr = 50 kW) is probably 42 years old and about as simple as you can get. The only replacement item is the pilot light thermocouple every 5 years or so. That is tempting fate!!!

So long as the water is inhibited, what is there to go wrong mechanically?

At some stage, I shall move my boiler, but my concern is that the replacement will not be as durable.

the listing of the building is certainly a complication when it comes to double glazing etc.  I have heard that sometimes secondary glazing is accepted as an alternative that does not mess up the external appearance. I also think that if the govt is serious about its green agenda, it is going to have to become  a lot less sensitive about this sort of thing in future, or perhaps delist a lot  of the less exciting currently listed buildings that are actually also working buildings and really will need to be made efficient.

Fully understand the lack of appetite for confronting bureaucracy,, and suggest that not changing the boiler until gas price makes it worthwhile or it blows up and cannot be fixed is a sensible course.

Mike.