Ämne: Greenline HT Plus E14 restarts again and again

[blumi]

Hello,

My name is Peter and we live in Hungary I joined this forum to get some with our HT Plus E14 heat pump because here in Hungary there is no support at all for IVT. This forum might be my only chance to find a solution, thank you for any .

Background:
We have been using an E14 since 2006. This year in April we had a problem with the heat carrier pump (it had short circuit) and had to change it. Everything was perfect except that the pump was running continuouasly  even when the IVT was in standby mode. It turned out that the wrong pump killed one of the triacs on the panel inside the control box. So we measured which one is wrong and replace it with a new one. Since then the Rego can switch on/off the pump and it runs only when it is needed. Perfect.

Problem:
Since the triac replacement we have been facing with some new problems (which do not exists before):

1. The IVT restarts again and again (not the Rego's boot process!). Once I start the heat pump the countdown process begins (300s) and the heat pump starts to make hot water (this time no need to heat). After 3-5 minutes the machine stops everything and the display shows the countdown again. And so on. The Rego does not boot only the countdown process and then the heat pump starts again. There is no alarm, no error on the screen (and neither in the log).

2. The new heat carrier pump has a display which can show the actual power, speed, flow rate, etc. and it seems ok, the delta T between GT8 and GT9 is about 6-7 degrees, the temperature of the compressor isn't so high (60-80 degrees, vary) but nevertheless I got "High-pressure switch has triggered". I cleared the filter wich was not so dirty, vented the air from the system, etc. And if I spot the alarm and acknowledge it immediately, the heatpump continues the work and sometimes alarm again in 5-10 sec, but its vary.

I ordered 2 electrolyte capacitors to replace the old ones but they don't seem problematic at all.

If you have any idea, please us. This forum is my last chance, here there is nobody who can with IVT

Peter

[Rickard]

Older IVT hade problems with "magnetite" scaling inside the flexible houses for the heat water flow inside the pump.
To low flow might trigger the high pressure switch when the pump is trying to heat the hot water tank.
I am not shure this is the problem for you, but there has been a lot of people in Sweden having this problem.
Some people just cleans the houses, but most change them to a better quality.

[Roland]

I do not think there is a problem with the flexible hoses. The temperature difference GT8/GT9 is what it should be and the compressor temperature is also normal. If there is a problem with the flow to the condenser the temperature values should indicate that.

My theory is that the wrong type of circulation pump also damaged something else in the control box. Try to check whether the high pressure switch is really triggered when this is indicated. The voltage drop over the high pressure switch should change.

[blumi]

I do not think there is a problem with the flexible hoses. The temperature difference GT8/GT9 is what it should be and the compressor temperature is also normal. If there is a problem with the flow to the condenser the temperature values should indicate that.

My theory is that the wrong type of circulation pump also damaged something else in the control box. Try to check whether the high pressure switch is really triggered when this is indicated. The voltage drop over the high pressure switch should change.

The new circulation pump is a Lawara ecocirc XL 25-80 which is the compatible pump from Lawara with the original Wilo and has been working for months. To check the trigger I should catch the moment of the alarm? It won't be easy, I think.

[blumi]

I do not think there is a problem with the flexible hoses. The temperature difference GT8/GT9 is what it should be and the compressor temperature is also normal. If there is a problem with the flow to the condenser the temperature values should indicate that.

My theory is that the wrong type of circulation pump also damaged something else in the control box. Try to check whether the high pressure switch is really triggered when this is indicated. The voltage drop over the high pressure switch should change.

Can you me where should I find the high pressure switch?

[Rickard]

@Roland:
Yes, i am not shure, exactly by the reasons you give Roland, my guess was that the temp sensors might show wrong values, and that the compressor temp reading does not react fast enough in order to reflect the actual temp of the compressor or heat gas.
all due to low flow that effects the temp sensors inside.

Your theory is slightly better, but i am having problems seeing what in the "electronic control unit" might be wrong, making the high pressure alarm trigger without a actual change of pressure sensor switch detected.

It might be that the high pressure sensor is broken, always indicating high pressure, and that the software blocks the sensors function for the first 3 minutes the compressor is turned on, this would be a more logical fault i think.
If so, when measuring the high pressure sensor, check if it indicates high pressure all the time if it does not switch when the alarm is triggered.
The "no switch" might be "Always high" in that case, you need to know if the pressure sensors is normally open or normally closed in order to know this by measuring.
It probably is normally open, but i am not sure. If so, a healty pressure sensor should show 230 V over the sensor when pressure is low or normal, and 0 V when pressure is to high.

You need to turn to the manual to see where to measure the pressure sensor switch, you dont need to find the actual sensor.

[blumi]

Do you have any idea about the stop-start countdown frequently during making hot water without any alarm, error? It might be a control box related issue?

[Rickard]

Its the start delay, always there when the compressor is stopped by any reason, or if you turn of power to the machine.
It is to protect the compressor from starting agains high pressure.
The start delay gives the pressure time to equalize over the condensor/kompressor and/or valves.

[blumi]

Its the start delay, always there when the compressor is stopped by any reason, or if you turn of power to the machine.
It is to protect the compressor from starting agains high pressure.
The start delay gives the pressure time to equalize over the condensor/kompressor and/or valves.

I think it is clear the delay process which protects the compressor against high pressure. But the question is related to why on Earth stops the heating process without any alarm or error after 2-3-4 minutes from the starting. Is it a control box issue?

I would like to extend the background info:

It was in April this year when the original Wilo pump went down with short circuit. We replaced the pump and the IVT has been working for almost half a year without any problem, any alarm. It was summer, so only the hot water mode of operation was active. In September we realised that the pump is working continuously even if the IVT was in standby mode. It turned out that the triac which switches pump thru the P2 connection has broken (I think it was because of the pump fault in April) and not disconnect the pump. We measured almost everything in connection with this fault, found the triac and replaces it on the panel (in Rego 637). Since then the Rego switches the pump correctly, it runs only during the heat making and stops when everything is stops BUT the high-pressure switch alarms came up. So these alarms started not with the pump replacement, there were almost 6 months between them.

I read a lot about the 2 big capacitors on the panel after a while these cause some problems. Should I replace them with new ones, could it solve some problems? I can attach a photo of the capacitors.

[blumi]

Or I should clean the hoses (or replace with brand new ones). I'm a bit afraid of detaching the old hoses as they are 17 years old and can be damaged during the cleaning "massage".

[Rickard]

The most easy thing to do, that costs nothing, is to measure the high pressure sensor, i would start with that.
If the compressors stops within 3 minutes, you should be able to see if the pressure sensor really is changing over to alarm mode.
Just stare at the multimeter. 

If the pressure really gets high, at "low" temp, it should be a faulty high pressure sensor.
If the pressure gets high due to a faulty expansion valve the temp should also get high (I think)
If the pressure gets high due to low flow, the temp should also get high.
If you had a gas leak, the temp should get high, but the pressure would not get high. (Low pressure alarm at suction side)

I still think you need to check the pressure sensor, and try to make sure you have got flow, if the flow is nearly zero, its impossible to depend on the temperature sensors readings, they might not "have time" to heat up before the high pressure alarm stops the compressor.

It can of course be a faulty PCB, or it might be enough to replace the capacitors, but usually a bad capacitor is "swollen" on top.
Changing PCB and/or houses is the most expensive, i would save that to last.

[blumi]

The most easy thing to do, that costs nothing, is to measure the high pressure sensor, i would start with that.
If the compressors stops within 3 minutes, you should be able to see if the pressure sensor really is changing over to alarm mode.
Just stare at the multimeter. 

If the pressure really gets high, at "low" temp, it should be a faulty high pressure sensor.
If the pressure gets high due to a faulty expansion valve the temp should also get high (I think)
If the pressure gets high due to low flow, the temp should also get high.
If you had a gas leak, the temp should get high, but the pressure would not get high. (Low pressure alarm at suction side)

I still think you need to check the pressure sensor, and try to make sure you have got flow, if the flow is nearly zero, its impossible to depend on the temperature sensors readings, they might not "have time" to heat up before the high pressure alarm stops the compressor.

It can of course be a faulty PCB, or it might be enough to replace the capacitors, but usually a bad capacitor is "swollen" on top.
Changing PCB and/or houses is the most expensive, i would save that to last.

@Rickard, thank you!

I try find in the manual where can I measure the pressure sensor, but I'm not an expert could not find it I have a multimeter, I can use it but the place where I should measure ... that's the question.

[Rickard]

Just back from vacation, i have a lot of work to do, cant offer you the time need to search for you, but it should be possible to find online.
Try searching "installatörsmanual" and the heat pump model.
Or installers manual greenline HT plus

[blumi]

I think I found the high pressure switch (connected to HP sensor input panel), but no idea how to measure it

[Rickard]

If you can find the terminal, measure V AC over the two terminals, it should probably show 230 V in normal position, and 0 V when alarm triggered.
At least it should change state when alarm is active.