nowty wrote: ↑Sun Nov 21, 2021 6:01 pm
Stinsy wrote: ↑Sun Nov 21, 2021 5:44 pm
All good I assume? Are we calling it “fixed”?
No !
, but maybe it is now, I'm writing up something and will publish soon.
Problem update, the new 32A MCB still tripped a couple of times a day and even worse, an upstream 63A MCB also tripped and cut most of the power to the house off and left us in darkness until I worked out what had happened. That concerned me something was very wrong with the heat pump although it continued to work normally when I switched back on the power. And the local 13amp fuse to the heat pump was still not blowing so these MCBs must be very sensitive compared to a physical fuse.
It has randomly tripped in the past week either once or twice a day and I always assumed it must have tripped on start up, but I never managed to confirm that. Yesterday it tripped again but it was running at the time because it was heating up the hot water tank which still had not reached anywhere near the thermostat value. That made me think, either the compressor is knackered or there is something very simple I am overlooking.
I decided to re-check that all the water pumps were operating correctly. I have two per hot and cold circuit for redundancy. I had checked them last week, but one at the back is difficult to see because it’s covered in insulation and the LED is facing away from the front view. I thought I had confirmed it was working but I was not 100% sure so I waited until darkness today as the LED light on it is then easier to see using my camera on my phone.
The LED was off, so the pump had failed but that still did not explain the MCB trip as the heat pump still works with one water pump failure in each hot and cold circulatory circuits. However, when I removed the insulation around the pump, I found it was very wet with condensation.
I have had failures of these pumps before, and one was because of condensation on the cold circuit. Unfortunately, after I bought them, the instructions stated, “not to be used on liquids colder than ambient because of condensation.” But I thought I had fixed that problem by adequately wrapping a lot of insulation around them a couple of years back.
I noticed that both cold circuit pumps had condensation on them but the one that failed was from the flow side from the cold circuit of the heat pump so was running at 5 degrees colder than the other one on the return side of the cold circuit. That failed pump had more condensation running dripping off it.
I have two spare pumps, so changed the failed pump which is very easy to do and it’s all working again. I cut up an old towel into a long strip and wrapped it around both cold circuit pumps just above where the water was getting into the electronics. I am hoping this will soak up any condensation and it will evaporate off and not drip into the motor housing.
Its now been over 24 hrs without tripping so hopefully that was the fault and there is nothing wrong with the heat pump or the original 32A MCB. But I think another couple of days should fully confirm this.
