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Last seen: Aug 1, 2026
I have been writing down the temperatures on the probes on top of the buffer. High Point just prior to Defrost Cycle Two - 28.8C (significant drop...
Twi (Temperature Water In) is Hitachi's term for water returning to the Heat Exchanger. Remember, my temperature sensor are not metal probe...
This is the manifold. Zoom in to see actuators are removed.
The secondary pump runs all the time when there is a demand for heating and when in the Thermo Off situation. Yes the power cut turned the heat pump...
JamesPa. Data for the 26 November -4C OAT during night. 11C OAT during latter day. Water Temperature FIXED @ 31C. This temperature is a litt...
JamesPa I plan to send you a chart tomorrow of todays (26th) result. Just to make sure I am giving you what data you need.
I wish I had only 9 defrosts in that timeframe. I had 16 in the early morning of just the 26 Nov.
Sim0n0. I also have the Hitachi Yutaki system. Also having lots of problems.
Thank you for the reply. I think you are saying that what I am seeing is normal (Evaporator -23C. OAT -4C. Defrost cycle every 46 minutes). ...
You could be right in that it's a region between the 2 dotted lines. It's not clear to me what the chart really means, not my area of knowledge. May...
Concerned about the noise and build up of ice. I believe that the evaporator should not be getting down to -23C, based on the algorithm. If I am inte...
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Degrees of Separation
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@tomtheheatingengineer, thank you, and welcome to the f...
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