View Full Version : Is this bubbles/foaming/flashing R407C

08-01-2017, 12:51 PM
Hi Guys,

I'm writing from Sweden! Please excuse my awful English.
I have recently bought a house and this is my very first winter with the heat-pump so I'm trying to learn how it works and its needs to be taken care of.
Okey, so the heat pump is a geothermal heatpump, IVT Greenline HT plus C9, it has a 130m deep bore hole, and was installed about 9 years ago.

I read the fault log, and it states alot of "Heat carrier delta - high" during the past couple of years, so I have cleaned the filter on the warm side, and also increased the speed of the internal circulation pump, so now I have about 7 degrees C in deltaT between heat carrier out and in.

I have tuned all radiators to a deltaT of aprox 7 degrees between in/out.

I have experienced that, when the temperatures goes below 0 C, it starts kicking in the electrical heating. The past 24 hours, outside temp was down to -20 and I consumed 138 kWh electricity in 24h, i'd say that atleast 110 of them is the HP.

I have set heat curve to 5, and the indoor temp is 20 C, the roof/ceiling is only insulated awith aprox 10cm of wood chip/shavings. I'm planning to increase it with +300mm this spring.

I checked the manual and I have checked the sight glass for the R407C, the manual states that no bubbles should be there.
I'm not sure what I have, don't know if it's bubbles or foam or something else, haven't found any pictures or film that matches this.

So I filmed it, for easier troubleshooting:

Please have a look and tell me what I'm looking at

Thanks in advance!

Rob White
08-01-2017, 01:10 PM


Assuming there are no other faults with the refrigeration circuit
such as a blocked liquid line dryer, blockage in the high side heat
exchanger or a restriction across a valve,

that sight glass is showing clasic signs of short of refrigerant.

The sight glass is showing liquid and vapour mixed together and
it should only be pure liquid.

That is all that can be said from the info you have given, the thing
will need to be inspected by a qualified heatpump, refrigeration and
or heating and cooling guy.

Don't try to make any other adjustments before you have it checked out,
These systems are hermetically sealed and shoud be gas tight, so those
bubbles are an indication that there is an issue and it needs checking.



Ps, it might not beas bad as it sounds, when the sight glass bubbles it
could be because of a few issues, the most common and obvious is a
refrigerant leak, but it is not very short and you have noticed it before
the system got too bad, but get it checked out.


08-01-2017, 02:03 PM
Please get some numbers out,

What is the evaporating temp?
" " " condensing temp?
Condensing pressure?
Is there any component that keeps condensing or evaporating temp at a given setpoint?
Looks to me from your video that you have over condensing [too low condensing temp]

Was the unit serviced at any time before the winter?
Can you check with the previous tenants if they had similar problems in the winter and what did they do?

monkey spanners
08-01-2017, 02:52 PM
Was there bubbles in the sight glass before you increased the speed of the pump?

The Viking
08-01-2017, 03:04 PM
Hej SX3000,

As others have said, it could be one of many different causes of your issues/symptom.
However, as I know the Swedish legislation fairly well, I do believe that you have done everything you can do yourself. It is time to call in a professional.
I don't know whereabout in Sweden you are located but if you follow this link you should be able to find engineers in your area: http://skvp.se/search
(SKVP = Svenska Kyl & VärmePump föreningen)


08-01-2017, 08:16 PM
Thank you all!
I don't have the knowlage or equipment to provide you guys with more data, the unit itself does not present any data of interest regarding the refrigiration, only temps of heat carrier, brine water, compressor etc.
The Heat-pump have not been serviced at all, expect for replacing 3-way valve two times during its lifetime.

I can't tell for sure if the bubbles were present when running the internal CP on stage 1, but I decreased it to 1 and let it run for a while and the bubbles/flashing are still present, so I'm guessing they were there before I increased the CP.

"Looks to me from your video that you have over condensing [too low condensing temp]"
So, recharging won't help if this is the matter I guess?

The Viking, are you Swedish? :)
Thanks for the link, I found a Company nearby, will call them tomorrow and see if they are certified regarding recharging and repairing leaks.

The Viking
09-01-2017, 01:21 AM
Am I Swedish?
Now there is a question that could be debated at length...
But yes, i am a proud holder of a Swedish passport even if I nowadays have been fully indoctrinated in to the British ways.
I was in the first generation of engineers who had to qualify for "Svensk Kylnorm", some 29 (!?!?) years ago. But that qualification has probably lapsed by now as I have lived here in UK for the last 22 years. ;(