TimToos

Correct, I thought we would save money by not heating all rooms up. We dont use all rooms. Instead I let rooms cooldown during the night then come back up to temperature in the early hours, from 3:30m. Whilst other rooms we didnt use had their stats basically on frost protection only.

I need to check how the zones operate. Im sure its a motorised valve but not sure if zone 1 and zone 2 can be heated at the same time. Im not sure about the heat requirement or what I should expect. The house isnt particularly large but suppose its slightly bigger than a normal 'Wimpy' type affair. I cant remember the foot print buts its 5 bedrooms with ground, floor 1 and floor 2. We had the calcs done for the required heating etc and the ASHP was based on these figures. The cavitys have 75mm insulation and air gap and the roof and ground have 6" plus the tops rooms are boarded out with insulated board. Hopefully we can get the costs down.

You are right, just found the doc!! These are what it informs: Flow temp: 45C SCOP: 3.80 Est annual generation: 20305 Space heating: 16806 Water heating: 3499 Am I right to assume that if our SCOP is 3.8, and annual generation is 20305 then the ASHP power to be consumed is 5343? In our case, in 2021, the ASHP actually consumed was 5427 but the house was running on the room stats (set lower than as I thought this would save money) and so the system was most likely switching on and off like a yo-yo. Is this most likely my issue? If I run the system on 2 wireless controllers, one for zone 1 and one for zone 2 would this make the system function more efficiently?

Does anyone use the wireless controllers and receiver units? If I had 2 controllers, could I place one upstairs and downstairs and allow the ASHP system to run to these instead of the wall thermostats? Can the ecodan run both heating zones at the same time? Also, what about the MAC-567IF-E Wi-Fi Card? Does anyone use this for connecting to the MELCloud service and if so is it any good? What about the installation on the units onto the board? I cant find the manual on the actual fitment of this wi-fi unit, just the setting up of it. Thanks

Mitsubishi Ecodan ASHP - manufactured 03/19. ASHP: PUHZ-W112VAA Cylinder: EHPT25X-VKHCW

Yes, West Morton area BD20

Ive just had a look at some accessories and theres a wireless controller and receiver unit for this ASHP. Is this a worthwhile investment, installing this another room and controlling with this?

Hi, The ASHP has 5 thermistor sensors. Flow to and from temps, DHW tank, room temperature (utility room) and outside temperature. I was never told about these sensors so thats where its located, in the utility. Does anyone recommend someone who knows these systems and can fully set-up?

Doesnt it indeed? I dont know who to get in touch with who could advise.

What I dont understand is how the system knows the upstairs temperature. Theres a ASHP temperature sensor in the room where the cylinder is located (utility room). I have it to control to this sensor and set this at 21C. Zone 1 upstairs, only calls for heating from a t'stat as theres no probe for upstairs. So how will the system know when this zone is at setpoint? I ask this as both zones have a setpoint each, so downstairs (zone 2) will aim for 21C and upstairs (zone 1) 18C.

Hi RR, The house did and does qualify for RHI. YES are MCS accredited. All, I have changed these setting: Set all the downstairs room t'stats to 1C temperature higher than what I require. Changed the upstairs temperature to a temperature I require. Changed the ASHP to run with a fixed temperature. Zone 1 (upstairs) is set at 18C and zone 2 (downstairs) is set at 20C. Changed the HW tank setpoint to 49C. Left the 10C drop as it was. Thoughts?

Hi, we used a company in Harrogate. They did the system design and sized everything accordingly. I did question the how water tank saying I wanted a 300L (I like overkill) and he said that would be a waste of money, both for the tank and to run the system. He sized up the radiators for upstairs and the ones in the bathroom are too small, we now need to install a second one in the large bathroom. The more I live with this system the more I feel very cheated. We paid him on the dot and as far as I can tell hes walked away from our issues. I have emailed lots, even to talk about investing in solar PV, and still he has never got back. I think theres a lesson here... I wish there was some comeback as Im so annoyed.

You have got me worried now about the tank size. I did want a 250L cylinder when the installer came round and he said it would be a waste of energy as that volume of hot water would not be required. Now I am thinking that once the kids grow up will the 250L be too small?

Ive just looked, the tank is 250L. Is this still too small?

I feel installing a ASHP was rather a lie in terms of what we should except. Im not sure if GSHP would have provided a better and cheaper long term alternative. We, as an household, are using much more electric and running the house at lower temperatures, than was forecast.

Hi, RR, sorry, I have used both settings in the past but have its set to weather compensation. I have changed to fixed for a short period before realising this wasnt going to help.

Hi ProDave, This is very interesting and also worrying!

Hi JohnMo, many thanks for your reply. I will have a look at the site you recommend and see what I can do. Thanks

Hi all, We built a house and it was finished in 2019. Its to the latest build spec regards to insulation and the likes. Its over 3 levels, ground, first and second floors. Its 5 bedroom, two main baths, a downstairs WC and one en-suite. Downstairs the layout is a kitchen diner, utility with downstairs WC, living room and office. The two bedrooms and one bathroom on the top floor have their radiators all on frost stat upstairs so never come on. The first floor has radiators and 1 thermostat for the entire floor. Its set at 17C in the height of winter and I put it in the bathroom - which the temperature barely can reach. This floor is fully carpeted except the bathrooms which are Amtico vinyl. The ground floor is all UFH, with Amtico vinyl flooring. Each room with a Heatmiser thermostat. Last year (2021) was a mild year. I had the thermostats in the rooms we use (dining/kitchen the living room and the utility set at 18C. The hallway was set at 15C so was the office as we dont use these much or are just pass through areas. We have a Ecodan 11.5kW ASHP with 200L tank. There are 2 adults and 2 children, one 7 and the other 3. The DHW is set at 55C. Last year (2021) we used: DHW: Consumed (kW): 1807 Delivered (kW): 3185 COP: 1.76 Heating: Consumed (kW): 3620 Delivered (kW): 8457 COP: 2.34 2021 was a mild year but in 2020 when we got some real cold weather we used on some days over 75kWs/day, although we had the room temperatures at 21C not 18C. These COP values seem low. We expected at least 3.0 as the yearly average. With bill costs soaring, we are looking at what we can do. The installer isnt really helping at all. Does anyone have advice at all? I have just checked July/August usages: July DHW: Consumed (kW): 84 Delivered (kW): 173 COP: 2.06 Heating: (is this the heater for Legionella) Consumed (kW): 14 Delivered (kW): 0 August DHW: Consumed (kW): 80 Delivered (kW): 164 COP: 2.05 Heating: (is this the heater for Legionella) Consumed (kW): 15 Delivered (kW): 4 (The bathroom t'stat battery failed and called for heating) Thanks in advance.