Boiler / Radiator BTU Delta - Should I be using T50 or T60?

[vulcancontinental]

If you're going to get this involved do it right.

As mentioned on first page, www.heat-engineer.com. spend £10 +VAT, best part of a day learning and using it then you know where you're starting from.

I reckon much of the existing will be ok.

Rad sizes, new and existing and options are easy to swap and compare.

 

[desktop987456]

I was following the discussion because I had two boilers installed at home and I have decommissioned the second boiler and connected all rads 13 in total to 35kw boiler (no dhw on boiler). Installing the second boiler will cost you more for sure in terms of gas consumption. What was your decision in light of the advice on the forum.

 

[GeddyMortgage]

I was following the discussion because I had two boilers installed at home and I have decommissioned the second boiler and connected all rads 13 in total to 35kw boiler (no dhw on boiler). Installing the second boiler will cost you more for sure in terms of gas consumption. What was your decision in light of the advice on the forum.

Decent argument for both I guess.

Option 1 - Split Zoning ground floor / upstairs - seems expensive as someone will need to access the sections of the CH flow / return that T Off and run down the wall cavity to the ground floor. And from advice on this forum is ultimately no different than me just turning the rads off on those rooms?

Option 2 - Hive / Smart TRV valves on each rad - seems like the cheapest way to control the heating through the property but also more to manage and quite a granular way of achieving it. Plus buggered if wifi goes down?

My issue with the above options is - it looks like I can’t add any more radiators easily on the ground floor without upping the boiler size… and even if I did…with the boiler being in the loft of a 3 story property on the far right hand side, there’s some very long runs of pipe to get it to the ground floor rads and back. (Mentioned previously this was originally a bungalow so has a very wide footprint / floorplan, so not just vertically alot of ground to cover but horizontally too).

Which leaves me with

Option 3 - 20/25kw system CH only boiler-
to serve ground floor radiators. Of which there’d be 12-14 rads. Yes more expensive to run both at same time but sounds like I’ll need to increase the size of my upstairs one anyway if I don’t add a second one.

I also like the idea of them being able to be run independently with plenty head room on either and the rads would all have a much closer average to their respective boilers, ideally I’d take this opportunity add 3 more reds on ground floor than currently…and to also upgrade the middle top floor type 11 rads to type 21/22. As should have plenty head room to do that then too.

 

[desktop987456]

I agree but with rising fuel prices, I would invest in insulating the property first and may end up in installing two boilers running independently but I would not be worrying about their efficiency then. Just my two cents worth after running two boiler operation which was very inefficient and way oversized for my needs.

 

[GeddyMortgage]

Yep, insulation is in hand regardless.

None of the pipes were lagged in the cold loft space. A good 80m or so in total. Now all 22mm 19mm collar lagged and wool over them.

Most loft had 100mm insulation, some had zero!… now has 300-400mm apart from the super difficult to access areas.

Sub floor now has 200mm insulation

And we even did an air test for drafts etc, all of which has been addressed too (mostly silicone and foaming skirts / window frames etc)

Even with all that my gut is saying ground floor boiler is the one. For the reasons above.