Wanting to reduce gas usage - New Heating Design Circuit - will it work?

Solarchaser

Just to echo what Michaels is saying, id definitely think about some sort of blending valve.
For me it's just a gate valve between the in and out, that ive manually been adjusting to get roughly 55C otherwise I'm seeing temperatures of over 75C in the radiators, and thats bloody hot, too hot by half for little people to touch, and quite a bit of thermal shock to the rads (a fair bit of creaking as the heat starts to come through).

Freepost

Hi,

I most definitely intend to use a TMV to reduce the temp from the Cylinder. Unfortunately the majority of TMVs  are for DHW and have the upper temperature limit set at 45°C. I think a higher temperature will be required for the central heating rads, say 55 ~60°C.

michaels

Freepost said:

Hi,

I most definitely intend to use a TMV to reduce the temp from the Cylinder. Unfortunately the majority of TMVs  are for DHW and have the upper temperature limit set at 45°C. I think a higher temperature will be required for the central heating rads, say 55 ~60°C.

You can find them as I have used them before but they are more expensive.  What would be nice would be to find a wifi controlled one then you could run DIY weather compensation

Solarchaser

Freepost said:

Hi,

I most definitely intend to use a TMV to reduce the temp from the Cylinder. Unfortunately the majority of TMVs  are for DHW and have the upper temperature limit set at 45°C. I think a higher temperature will be required for the central heating rads, say 55 ~60°C.

I dont know you can really use a TMv as such as you have no cold water supply, only a return,  that's why I went with a manual valve instead.
However for the tmv for hot water I got a pegler valve, and the 45C output wasn't hot enough for the wife, but its able to be adjusted by Allan key,  so ours is closer to 50C, might even be 52C, so I guess what I'm saying is if you were to go with a TMV, you can adjust peelers to be hotter. 

This was the one I got, though I picked one up from ebay for alot cheaper than the screwfix price

https://www.screwfix.com/p/pegler-p402-tmv-22mm/60528

In fact there is one on ebay just now for much cheapness
https://www.ebay.co.uk/itm/134270703957?mkcid=16&mkevt=1&mkrid=711-127632-2357-0&ssspo=zKjF7-b9RHS&sssrc=2349624&ssuid=DtbsXk1pRsq&var=&widget_ver=artemis&media=COPY

zeupater

Solarchaser said:

Freepost said:

Hi,

I most definitely intend to use a TMV to reduce the temp from the Cylinder. Unfortunately the majority of TMVs  are for DHW and have the upper temperature limit set at 45°C. I think a higher temperature will be required for the central heating rads, say 55 ~60°C.

I dont know you can really use a TMv as such as you have no cold water supply, only a return,  that's why I went with a manual valve instead.
However for the tmv for hot water I got a pegler valve, and the 45C output wasn't hot enough for the wife, but its able to be adjusted by Allan key,  so ours is closer to 50C, might even be 52C, so I guess what I'm saying is if you were to go with a TMV, you can adjust peelers to be hotter. 

This was the one I got, though I picked one up from ebay for alot cheaper than the screwfix price

https://www.screwfix.com/p/pegler-p402-tmv-22mm/60528

In fact there is one on ebay just now for much cheapness
https://www.ebay.co.uk/itm/134270703957?mkcid=16&mkevt=1&mkrid=711-127632-2357-0&ssspo=zKjF7-b9RHS&sssrc=2349624&ssuid=DtbsXk1pRsq&var=&widget_ver=artemis&media=COPY

Hi

We don't have U/F heating, but do have a similar setup on solar thermal DHW with a whole house TMV, where cold&hot water are blended to supply DHW from >70C down to safe temperatures, but I have seen a number of setups where similar mixer valve arrangements are used for combined U/F & radiator systems, the one I'm thinking about at the moment does this at a manifold level with thermostatic control, but I'm also aware of at least one setup locally where blending was simply controlled through manually adjusting (/restricting) flow of both feed & return in the mixing process until a reasonable desired temperature was achieved, don't know exactly how safe this would be if the feed temperature or system flow through radiators was changed so that the return temperature became higher though ... I think in all cases there was a pump close to the manifold, but haven't looked at the various set-ups for at least 15 years or so, so couldn't describe the setup in detail ...       

Anyway, considering the above, wouldn't you just use an underfloor heating blending valve to lower the flow temperature of the feed by mixing from the return in the heating setup being looked at  .... a quick search just pulled up a number of 28mm U/F thermostatic blending units with adjustable mixed temperatures in the range of ~35C to ~60C with maximum input flow of ~90C & max operating pressure  around 5-6 bar ... they typically look to be in a range of £150-£200 though!

HTH - Z