If your ASHP has both a pressure sensor internally and isolation valves and you also have a pressure sensor one on the expansion vessel then you can isolate your ASHP leave for 24-48 hours and see in which half of the system the pressure has been lost.  Otherwise, you may be able to play similar games with any other bits of the system that can be isolated.

I dont see you have a redress against the service company, they appear to have taken reasonable action to fix an evident problem, its not really their fault that there appears to have been more than one problem.

Hello James.

Thank you for your reply.

My AWHP is a Samsung AE090JXYDEH , 2 x SWEP ID2-1414 heat exchangers and a Gledhill ABL250HP thermal store.  5 rads 2 towel rails and 90m2 underfloor heating.

The house is a new build with high spec. insulation and themal efficiency , the heating system was specified as part of the whole design. 

I can not find any valves on the Samsung unit, There are pressure gauges for the primary and heating circuits next to their prospective expansion vessels. Since these cicuits vary in capacity and along with the differances caused by temperature fluctuations it is hard to use these to diagnose the problem.

I suspect I might have to drain the primary circuit disconnect the ASHP and cap off the flow pipes to do a pressure test on the primary circuit and heat exchangers. 

If that fails, I think that I should then remove the heat exchangers and test them individually.

If I drain my system what ratio of glycol to water should I put back in ( I will measure the volume that comes out )

I know I am asking alot, but from experience , the warranty is as useless as the person who causes you to claim off it !

Cheers 

Alistair

If you have heat exchangers between primary and secondary the two circuits are isolated so a leak in one wont affect the other.  So whichever pressure gauge is dropping tells you which circuit to test.  If there are no isolation valves then yes you will need to drain and pressure test, but there isn't much between ashp and heat exchanger so im not sure that, if the leak is in the primary, a pressure test will tell you much that you can't determine buy visual observation.

Have I misunderstood how your system is plumbed?

The primary circuit from the Samsung unit transfers its heat to the secoundry / heating circuit through 2 metal plate heat exchangers.

 Do these fail and would that cause wierd pressure events across both circuits .

I am hoping this because they are cheap to replace compared to the heat pump or digging holes in the plaster to find a leak.

It is the primary that drops its pressure.

 I Will switch system off and top both systems up and pressure vessels and get result overnight ! 

Primary     at 20psi  1.4 bar

Secondary at 15psi  1.0 bar

I am hoping that by doing this i can find the area of fault and then hand it over to an engineer.

PHE s can fail, I'm not sure what the most common failure mode is.  If a plate separating the two circuits failed pressures will presumably equalise, if a plate between one circuit and the air fails presumably only that circuit is affected.

Results overnight may clarify!

Good morning !

I am writing this as I am dealing with the Samsung help line !

Two days ago I posted about losing pressure in my heating systems primary circuit.

Many thanks To James for replying!

Since then I have had the system turned off . After the initiall cool down of the system I checked all pressures and topped up as required.

I deliberately had the two circuits at different pressures .

Over night there has been a slight drop in pressure (1 to 2 psi) evenly in both circuits this I think is down to residual cooling.

Given that the system lost its Pressure over night when operating, would I be right in thinking the fault lies in the outside unit ?

 Given that it has no warranty. Can and is it worth repairing these things ?

Are there people who would take it on ?

If I have to replace the unit will the wiring and pipes be of the same standard ?

I know It is a big ask, but my faith in tradesmen is very low , I have a self build and have learnt that I can live with my own mistakes, but find it hard to come to terms with paying other people, to muck it up or not provide support .

Many regards

Alistair

P.s  heating not on the Samsung phone options. 

I have just been given a diferent number from the one on my paper work 0330 7262677 . I am going in !

Hi Alistair. I’m not an engineer but it sounds as if your analysis is correct to me. Perhaps others will be able to confirm. 

A replacement like for like should be a straight swap. I’ve fitted my own Samsung if that’s the route you want to take. 

Whoo hoo A number that worked , option 5 !

An engineer is going to call me back !!

Nick from Samsung has called me back . 

He has said that the system has had major trauma, and possibly for a long term, due to failure of the pressure vessel ,  and that it may take a while to expell all the air in the primary circuit !

Will keep the fill  loop attached and top it up as needed for a week , and then report back !

I will hope for the best, and admit that this help has quelled some of my cynacism ! Thanks Nick !

If only I had recieved similar attention from my service / installers !

Thankyou to all

Alistair

Just to update you all.

I made up my own fill loop as my installers had not left one for the primary circuit and used a special pump.  Eventually after many small top ups and bleeds over 5 weeks the system eventually held a constant pressure !

It was hard to be positive, thinking they were going to charge me a call out fee for every time the system needed topping up.

I have now found a local company who are much more reasonable on their charging structure !

Many thanks to those who helped !

Alistair

Posted by: @ohdearism

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Just to update you all.

I made up my own fill loop as my installers had not left one for the primary circuit and used a special pump.  Eventually after many small top ups and bleeds over 5 weeks the system eventually held a constant pressure !

It was hard to be positive, thinking they were going to charge me a call out fee for every time the system needed topping up.

I have now found a local company who are much more reasonable on their charging structure !

Many thanks to those who helped !

Alistair

I've always regarded topping up heating systems as my job not a plumbers. My gas system needed topping up about twice per year and no way was I going to pay someone else to do this given that it takes less than five minutes and they would have to travel whereas I am already on site.  Likewise cleaning filters.

Perhaps I'm just too mean!