Panasonic Air Source Heat Pump

[Rohan]

Purchased a Panasonic Air Source Heat Pump for central heating in 2015 which has a manufacturers 7 year extended warranty. The heat pump was installed by an accredited installer approved by Panasonic and has now developed a H65 fault. Been in touch with Panasonic who now say that some of the things were not done by the plumber (i.e. Buffer Tank not installed) so therefore we are not covered by the warranty. Feel very angry and not happy with Panasonic as this was an approved installer and no checks were carried out. Do I need to have a Buffer Tank fitted

[PeterW]

Depends .. what is your heating ..? UFH or rads ..? size of house..? Size of ASHP..?
 

Buffer looks optional with Panasonic but H65 depending on the model is either flow switch or primary pump. Both are fairly easy to resolve for an engineer. Is the pump integral to the unit or do you have a separate pump..? 

[Rohan]

I think the pump is integral but not sure. Panasonic have said that they recommend a buffer tank which should have been installed.

[TonyT]

Preferential engineering- I recommend lots of things but some are my preference not mandatory.

 

chase installer

[Rohan]

Have sent email to installer he has stated that buffer tank wasn't required but Panasonic say it was part of the installation. He is now no longer a accredited installer so it seems as if other things have gone wrong in other installations.

[Rohan]

We are in a 4 bed detached house with underfloor heating downstairs and rads upstairs with a 16kw LT system.

[NSS]

We have a Panasonic Aquarea T-Cap. Not sure how different it is to yours, or whether this is any help, but we had this fault and it was the water pump (it had seized). Unit was circa 2.5 years old at the time (4.5 years old now) and Panasonic supplied replacement without even needing to see the faulty one (which suggests it wasn't the first) and paid a fixed fee to our installer to replace. 

[jack]

Interesting. We had a water pump problem with our 2015 Panasonic Aquarea ASHP about 3 years after installation, and it needed replacing.

 

No extended warranty as it wasn't installed by an approved installer.

 

The part cost was a ridiculously high proportion of the unit. I want to say it was something like £400 for the pump, when you could buy the entire ASHP unit new for around £2k.

 

Who was supposed to back the warranty? Generally I'd have said that was the manufacturer.

 

Also, if it's anything like ours, the requirement for a buffer tank is set out in the installation manual. For ours (5kW), I believe it was needed if the system volume was less than 50L. 

 

If you meet the system volume requirement, I'd have thought Panasonic doesn't have a leg to stand on. Even if you didn't, I don't think they can hide behind the installer. What does the paperwork say - was the warranty in writing?

[ProDave]

Why is a pump so expensive?  Mine uses a standard central heating circulating pump, a Wilo in my case, easy and cheap enough should it need replacing.

[jack]

I just checked and the cheapest we were able to find it was £380. No idea why it's so expensive.

 

I spent some time trying to find a generic substitute at the time, but from memory, it's a proprietary part.

[Temp]

Does it have to be inside the ASHP or could it be anywhere in the pipe run?

[PeterW]

Most likely it is a variable flow pump controlled directly from the control board within the unit. Replacing it with something outside the unit would need some clever wiring plus a pump of equal spec so not simple. 

 

[jack]

13 minutes ago, PeterW said:

Most likely it is a variable flow pump controlled directly from the control board within the unit. 

 

That's exactly the situation.

[Rohan]

13 hours ago, jack said:

Interesting. We had a water pump problem with our 2015 Panasonic Aquarea ASHP about 3 years after installation, and it needed replacing.

 

No extended warranty as it wasn't installed by an approved installer.

 

The part cost was a ridiculously high proportion of the unit. I want to say it was something like £400 for the pump, when you could buy the entire ASHP unit new for around £2k.

 

Who was supposed to back the warranty? Generally I'd have said that was the manufacturer.

 

Also, if it's anything like ours, the requirement for a buffer tank is set out in the installation manual. For ours (5kW), I believe it was needed if the system volume was less than 50L. 

 

If you meet the system volume requirement, I'd have thought Panasonic doesn't have a leg to stand on. Even if you didn't, I don't think they can hide behind the installer. What does the paperwork say - was the warranty in writing?

Hi Jack Panasonic had sent me some diagrams from the installation manual showing a buffer tank should be installed although the commisioning paperwork says that the primary water volume is 50ltrs. The warranty is in writing but they are saying it is not a unit fault but due to no buffer tank and will not honour the warranty until it is installed. I have been in touch with the installer who said that it did not need one and has not fitted any buffer tanks to his system. Same old story everybody having sloping shoulders.

[jack]

53 minutes ago, Rohan said:

Hi Jack Panasonic had sent me some diagrams from the installation manual showing a buffer tank should be installed although the commisioning paperwork says that the primary water volume is 50ltrs. The warranty is in writing but they are saying it is not a unit fault but due to no buffer tank and will not honour the warranty until it is installed. I have been in touch with the installer who said that it did not need one and has not fitted any buffer tanks to his system. Same old story everybody having sloping shoulders.

 

Does the installation manual say that a buffer tank must be installed? Or just that it should be? If you can find something in the same manual saying that it's only needed if less than 50L system capacity, I don't see how they have a leg to stand on. 

 

Even if it's an installation fault, isn't that the whole point of them requiring that you use an approved installer? What does the warranty say about the installation, if anything? 

[PeterW]

@Rohan what is the make and model number for the heat pump ..?

[jack]

From the installation instruction manual for my 5kW Aquarea model (WH-MDC05F3E5):

 

I interpret this as suggesting a buffer tank is not required. I believe there's a small internal buffer in the unit, hence the use of "additional" here.

 

And the troubleshooting section says this:

 

 

I assume "is used" is a typo for "if used", which again suggests that a buffer tank is not compulsory.

 

As an aside, the (Panasonic-authorised) engineer who fixed mine suggested that a buffer tank was desirable irrespective of what the manual said.

[Temp]

Google found this but I don't know if this is a totally different model..

 

https://heidi-air-conditioning.co.uk/assets/downloads/user-manuals/panasonic-aquarea/End-user-guide-F-and-G-series-A2W_HR.pdf

 

"H65     Defrost circulation error     Reset once if reoccurring contact your local Panasonic installer, quoting fault code"

 

 

 

[Temp]

5 hours ago, jack said:

From the installation instruction manual for my 5kW Aquarea model (WH-MDC05F3E5):

 

I interpret this as suggesting a buffer tank is not required. I believe there's a small internal buffer in the unit, hence the use of "additional" here.

 

And the troubleshooting section says this:

 

 

 

 

 

Oops I miss read that as DEVICE circulation error whereas it says DEICE which is same as DEFROST.  

[Temp]

So are they saying you need a nice big buffer tank full of hot water to defrost it when it ices up? 

 

Could "Buffer tank (is used)" mean "Buffer tank (is used up/cold)"?

 

 

Edited December 14, 2020 by Temp

[dpmiller]

if so why would a new pump fix it?

[Rohan]

8 hours ago, PeterW said:

@Rohan what is the make and model number for the heat pump ..?

Panasonic WH-UD16FE5

[Temp]

1 hour ago, dpmiller said:

if so why would a new pump fix it?

 

Pure speculation but..

 

Perhaps if the pump is failing the controller thinks it needs a defrost cycle. If that involves pumping hot water from the system/buffer it seems reasonable it might generate a defrost circulation failure error. Perhaps it tries to do a defrost but because the pump is failing the flow temperature  falls and it thinks its out of hot water to do the defrost. 

 

I'm making this up as I go along so happy to be corrected if this is wrong.

[PeterW]

3 hours ago, Rohan said:

Panasonic WH-UD16FE5

So in the MIs it states the following :

 

 

Go back to Panasonic, quote their own MIs

and say this did not require a buffer as over 50 litres. Give them the exact reference above and then ask them when they would like to send their engineer .... 

[SteamyTea]

23 hours ago, jack said:

As an aside, the (Panasonic-authorised) engineer who fixed mine suggested that a buffer tank was desirable irrespective of what the manual said.

I am coming to that conclusion, this possibly the exception of swimming pools.