Ämne: Greenline HT Plus E14 restarts again and again

[blumi]

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.

I have disconnected the connector from the terminal and measured resistance between the two wires. It showed almost 0 ohm (2-3 ohm exactly). I've checked the low pressure switch as well with the same result.

[Rickard]

I does not say anything as long as you dont know it the sensor is normally open or normally closed.
2-3 ohm is not 0, it seems a bit strange, it should either be close to 0 ohm or open circuit.
Is there 230 V on either of the terminals when the heat-pump is powered? (Might be o lower DC-voltage also, i dont know.)

[blumi]

I does not say anything as long as you dont know it the sensor is normally open or normally closed.
2-3 ohm is not 0, it seems a bit strange, it should either be close to 0 ohm or open circuit.
Is there 230 V on either of the terminals when the heat-pump is powered? (Might be o lower DC-voltage also, i dont know.)

Thanks, Rickard I try to do my best, but I'm not an expert.

If I unplug the high pressure switch from the terminal (HP port) when the heat-pump is powered:

1. the Rego alarms a "high pressure switch"
2. there is no voltage on the terminal HP port (where the high pressure switch was plugged)

and I measure 5,4 ohm on the standalone high pressure switch (I can measure it only at the end of the wire).

In addition: in the last 2 days we had no HPS alarm ...

And again, thanks for your .

[Rickard]

OK, if the unplugged sensor gives you the alarm it should be a normally closed function on the sensor.
When it opens (When you unplug it) the alarm is created.
This tells me that the sensor (if there is a problem with the sensor) triggers to fast, it obviously works when pressure is low since the alarm goes away then.
Try "Knocking" on the sensor with the handle of a screwdriver, that has been a way to get it to work for a while on other heat pump HP-sensors.
But if this solves the problem for now, you should consider getting the sensor changed.

[blumi]

OK, if the unplugged sensor gives you the alarm it should be a normally closed function on the sensor.
When it opens (When you unplug it) the alarm is created.
This tells me that the sensor (if there is a problem with the sensor) triggers to fast, it obviously works when pressure is low since the alarm goes away then.
Try "Knocking" on the sensor with the handle of a screwdriver, that has been a way to get it to work for a while on other heat pump HP-sensors.
But if this solves the problem for now, you should consider getting the sensor changed.

@Rickard, thanks!

I did some knocking on the switch and we will se the result. The malfunctioning high pressure switch can cause the short time switch off (and delayed restart) of the complete hotwater production? In this case there was no high pressure swicth alarm, only stops everything and restart in 300s. Or it is different issue?

Thanks

[Rickard]

I am not shure how IVT handles the HP-alarm, if it restarts by itself, or if you need to erase the alarm.
Lets wait and see if your work made any difference.
And i dont know what you mean with "switch off", does all of the machine get dark, as if the power is out?

[blumi]

I am not shure how IVT handles the HP-alarm, if it restarts by itself, or if you need to erase the alarm.
Lets wait and see if your work made any difference.
And i dont know what you mean with "switch off", does all of the machine get dark, as if the power is out?

I mean (on switch off) that the IVT shut down the heat carrier pump, compressor and everything except the control box, like when the water temperature reaches the target value and it stops producing heat water.

[blumi]

It seems the high pressure switch alarms have gone. Any ideas about the restarting (not rebooting!)? These restarts occur only when in hot water mode, during heating mode the heat pump does not restart.

[blumi]

Anyone have any ideas about restarts?

[Börje__]

Anyone have any ideas about restarts?

Pls here some brainstorming....

Maybe you already wrote somewhere But what is GT3 showing from start and to when vp make interrupts and what are the settings?
Maybe just switch this with another one same you have in the pump, to be sure it's working okay?

And the flowrates Gt8/9 are the same for heating and warm water?  E14 means it's a separate water tank, is it original IVT?

Have you manually logged all the sensor every minute until it stops? Looks normal?

[blumi]

Pls here some brainstorming....

Maybe you already wrote somewhere But what is GT3 showing from start and to when vp make interrupts and what are the settings?
Maybe just switch this with another one same you have in the pump, to be sure it's working okay?

And the flowrates Gt8/9 are the same for heating and warm water?  E14 means it's a separate water tank, is it original IVT?

Have you manually logged all the sensor every minute until it stops? Looks normal?

Yes, we have a separate hot water tank connected to the IVT, and it isn't an IVT tank, it is a Heizer (Italian brand as I know). They have been working together since the beginning. The GT8/GT9 delta is OK, 5-6 degrees in both modes. I've checked the flow rate on the heat carrier pump (it has a digital screen, showing flow rate, speed, consumption, etc.) and turned out that the flow rate (speed) of the heat carrier pump is less when the IVT makes hot water than when it runs for heating. And during the hot rad mode it does not stops just when it reaches the necessary return temperature. So it looks like there might be something with the hot water tank or the pipes go there. I read an article about it, when a hot water tank has not enough big heat exchanger (or it goes broke) the return temperature may be too high and the heat pump may stops but in the tank, the water temperature is less then the expected (set it on the heat pump). And (because the water temperature is not high enough) it triggers the heat pump to make hot water and it can be a never ending loop, until the heat pump fed up with it and stops making hot water.

I think we will check the hot water tank (and it's heat exchanger) whether we can see anything strange around it.

Or any other idea?

[Börje__]

I would not assume that the Gt8/9 delta for hot water necessary should be 5-6° low, could be a paradigm in your case.
The Gt3 starts and I also think it stops the hot water production, so maybe you can find the logic in addition to your heat exchange investigation as well.

[blumi]

I would not assume that the Gt8/9 delta for hot water necessary should be 5-6° low, could be a paradigm in your case.
The Gt3 starts and I also think it stops the hot water production, so maybe you can find the logic in addition to your heat exchange investigation as well.

I've checked the GT8/GT9 during hot water mode. As I see the IVT stops because of the GT9, when reaches the 57 degrees (in the manual: The heat pump stops at 57oC for reasons of safety.) before GT3 reaches the target temperature. Can it be caused by a wrong heat exchanger in the outside water cylinder?

[Börje__]

I can imagine that.

so if you reduce the speed of the cirkulation pump to get a higher delta (10-15° should work)

&/or set to a lower hot water temperature

&/or increase the efficiency of the heat exchanger i.e. try to to clean it, with suitable acid or what's needed.

This is what I would consider to test,
 maybe some other here in forum can can advise as well.

[blumi]

I can imagine that.

so if you reduce the speed of the cirkulation pump to get a higher delta (10-15° should work)

&/or set to a lower hot water temperature

&/or increase the efficiency of the heat exchanger i.e. try to to clean it, with suitable acid or what's needed.

This is what I would consider to test,
 maybe some other here in forum can can advise as well.

Thanks for your . If I reduced the speed of the heat carrier pump I think the IVT would throw an alarm on the heating mode with high delta (it used to be). The hot water temperature is not so high, only 43 degrees. So I think the heat exchanger cleaning or change will be the next step and we will see the result.