ASHP-user

Thank you all. Some more great advice. Will monitor and record setting and track energy use also. Now also understand the combination of the central hall controller together with the smart per-room controls. Thank you @Marvin and @JohnMo. My ASHP was a retrofit of a gas boiler with gravity hot water to a pressurised indoor unit with a separate 210l cylinder. It really does not need bigger rads, although I have yet to experience a really cold spell. The Daikin high temp design is quite clever. Check outline here. The downstairs rooms are nice and warm. Shortly, probably 1st April, coinciding with the energy hike, will turn off the heating and get the system drained and TRVs and heads installed. Still have several rads without TRV or 26 year old incompatible and clogged up TRVs.

Thank you all. Slowly with a 2 degree variation does it. With or without TRVs, also set to small variations. My system is high temp, so rads are about 60 degr. not 35-38 degr. @JohnMo if the hall main stat is set to, say, 20 degrees and the nearby TRVs to 18 degrees, does that not mean that the ASHP will keep on pushing to get to 20 but never gets there? Hence, better to disconnect the main hall thermo if possible and let TRVs control the ASHP? I'll reach out to Daikin also.

Thank you TW9 and ReedRichards. Clearly not a simple black-white subject. I had previously configured a schedule that would turn off the system at night. That resulted in a big increase in electricity use as, I assume, the system had to work hard in the morning to bring tank and rads back to its desired temperature. Keeping it on constantly has been better. I agree that the hall is a poor location for the thermostat. Basically the hall, landing and living room are all controlled by the one thermostat. I do believe that keeping hall and landing a couple of degrees below the living room, and keeping living room door closed, will better control the spaces. But overall keep within a hysteresis that avoids the heat pump having to work too hard. I'll also check out Heat Geek. May also have to review the design assumptions and see if anything else can be adjusted. I'm still mindful to get the extra TR92s (or manual TRV heads) in my hall, landing and living room. Will post back an update with any conclusions.

I'm a new ASHP convert. Have recently installed the Daikin Altherma 3 H HT with the compact indoor unit and a separate pressurised water tank. I requested a Honeywell Evohome to control all my rads with TR92 heads. Only few were installed in rooms outside of the main zone Daikin hallway thermostat. If the main zone switches off as warm enough, the bedrooms stay cold. Would it be OK to upgrade the main zone with TR92s so the whole house is controlled by Evohome? Would I need to disconnect the Daikin thermostat? I would lose the ability to change hot water temperature and booster function, but a can do that on the boiler control panel also (or main install Daikin WiFi module) Does creating these multiple zones have an adverse impact on the ASHP efficiency/ performance?