thefoxesmaltings Posted January 6 Share Posted January 6 Trying to do a bit of investigation as to why the house is feeling a bit cold. Currently at 19c, when thermostats are set to 21c. The leaving water temp according to my ASHP Daikin controller next to the water tank is 31c, yet on the UFH manifold, it's reading 25c on the manual thermometer (and upstairs as low as 20c). - Is this normal, and expected? Link to comment Share on other sites More sharing options...
MikeSharp01 Posted January 6 Share Posted January 6 Sounds more like you are reading the return temps doesn't it. ASHP output temp does feel a bit low though. Are you getting domestic hot water from the system reliably? Link to comment Share on other sites More sharing options...
thefoxesmaltings Posted January 6 Author Share Posted January 6 7 minutes ago, MikeSharp01 said: Sounds more like you are reading the return temps doesn't it. ASHP output temp does feel a bit low though. Are you getting domestic hot water from the system reliably? I'm not sure if those are return temps. It's the only thermometer on the UFH manifolds. Apologies, I am still learning! Yes, we are getting DHW fine from the system reliably. No issue with that. There are two separate tanks within the hot water tank. One for UFH and one for DHW. The DHW is around 45c and set to come on a schedule. Link to comment Share on other sites More sharing options...
JohnMo Posted January 6 Share Posted January 6 From title seems you may have a buffer, which will be the other cylinder. Are you running lots of zones? Also you may need to balance the flow rates either side of the buffer to eliminate mixing in the buffer. If your house is cold assume you are not trying to run for short periods? If running WC your curve at the cold ends needs to run hotter. Link to comment Share on other sites More sharing options...
MikeSharp01 Posted January 6 Share Posted January 6 WC = Weather compensation. 1 1 Link to comment Share on other sites More sharing options...
thefoxesmaltings Posted January 6 Author Share Posted January 6 16 minutes ago, JohnMo said: From title seems you may have a buffer, which will be the other cylinder. Are you running lots of zones? Also you may need to balance the flow rates either side of the buffer to eliminate mixing in the buffer. If your house is cold assume you are not trying to run for short periods? If running WC your curve at the cold ends needs to run hotter. We've got 8 zones, split across 4 UFH manifolds and pumps. How would I go about balancing the flow rates either side of the buffer? No, not running for short periods, it's on 24/7, minus a 3 hour window where the electricity rate is higher, so we don't call for heating demand during 4-7pm, but that's it. Weather compensation curve is set to max 35c at -5c external temp. I could try increasing the external temp to say -3/-2? Link to comment Share on other sites More sharing options...
JohnMo Posted January 6 Share Posted January 6 Move the max flow temp a degree or 2 hotter at-5 and see what happens. I am assuming the tank temp is the DHW not your buffer, your plate heat exchanger inlet temp is the same as the gauge so that is your return temp. Leaving temp is 31 so that's the flow temp. Link to comment Share on other sites More sharing options...
joth Posted January 7 Share Posted January 7 Do the manifolds have circulation pumps and thermostatic mixing valves? Are they set high enough? (Basically should only be set as an emergency high temperature shut off, depending on floor surface fragility) Link to comment Share on other sites More sharing options...
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