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JamesPa

@jamespa

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Joined: Apr 3, 2023
Last seen: Aug 7, 2025

Topics: 17 / Replies: 2679

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RE: Hitachi Yutaki SCombi Heat Pump - Thermal Off's

Can you explain what you mean by 'off' please? If they are off how is that affecting the heat pump/circuits. If you are getting a SCOP of 3.5 what ...

4 months ago

Forum

Air Source Heat Pumps (ASHPs)

RE: Efficiency Concerns on newly installed Mitsubishi Ecodan 8.5kW

@cbrenewable Hopefully the diagram shows one of the valves in the wrong place, otherwise there is a valve in the wrong place. Any idea why two pumps...

4 months ago

Forum

Air Source Heat Pumps (ASHPs)

RE: Hitachi Yutaki SCombi Heat Pump - Thermal Off's

@trebor12345 Hi. What is it you are still trying to solve/understand. I will see if I can help. Definitely that is a 4 port buffer.

4 months ago

Forum

Air Source Heat Pumps (ASHPs)

RE: Efficiency Concerns on newly installed Mitsubishi Ecodan 8.5kW

@CBrenewable A COP of 2.4 is definitely low and you are right to be concerned. You should be seeing 4 or better at present. Can you tell us s...

4 months ago

Forum

Air Source Heat Pumps (ASHPs)

RE: help sizing rads based on room by room heat loss

4 months ago

Forum

Thermostats, Volumisers, Buffer Tanks, TRVs, Pumps, Piping, Valves, Radiators & Controls

RE: help sizing rads based on room by room heat loss

Have you got the loss calculations, if so perhaps you could post?

4 months ago

Forum

Thermostats, Volumisers, Buffer Tanks, TRVs, Pumps, Piping, Valves, Radiators & Controls

RE: help sizing rads based on room by room heat loss

The output of a rad is proportional to DT to the power 1.3, where DT is the average temperature difference between rad and room. At a flow temperatu...

4 months ago

Forum

Thermostats, Volumisers, Buffer Tanks, TRVs, Pumps, Piping, Valves, Radiators & Controls

RE: Ecodan - is there actually such a thing as a 'minimum' flow temp to avoid cycling, and why if so?

Just to clarify this was a serious question, its going to be easier to explain your observations above if you have plots. If you dont then just say a...

4 months ago

Forum

Air Source Heat Pumps (ASHPs)

RE: Ideal Logic ASHP - change from 55°C to 35°C Heating?

Ok on second thoughts scrub the questions. Id be tempted to optimise the rads as previously described. If you find that this results in a rad curve ...

4 months ago

Forum

Air Source Heat Pumps (ASHPs)

RE: Ideal Logic ASHP - change from 55°C to 35°C Heating?

Ok. When you say max 50 what changes it? Does it in practice run at 50 and if so does the zone valve switch it on and off? Basically I'm trying to...

4 months ago

Forum

Air Source Heat Pumps (ASHPs)

RE: Ecodan - is there actually such a thing as a 'minimum' flow temp to avoid cycling, and why if so?

@rhh2348 have you got graphs to illustrate this, if so can you post them please (or were you sitting and watching?)

4 months ago

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