Vaillant Arotherm Plus issues - circulation, efficiency and performance – heat pump horror story
Hi there,
I an living in a heatpump nightmare at the moment. New ASHP installed last year, endless leaks and pressure drops occuring daily led to repair that involved removal of buffer vessel, PRV and the system being injected with a leak sealer. Then the pump broke down completely with error messages appearing 'compressor blocked/flow rate too low'. Repair people been out to check filter, not that. I have no heating and hot water so was told to use the immersion. It is run via the heat pump power supply and this switch (picture attached). However, I have noticed that the tank temp sensor is dropping, the circulation pump that generally only comes on when heating is being called for is now running constantly (for no purpose because the heatpump cannot provide it at the moment?). Is this pump running cool water through the coil in the tank and cooling the water that the immersion is trying to heat? Help! I am so cold and fed up. (the immersion is not wired in to its own separate supply.
That sounds like a horror @saz. Like you, we suffer from regular low flow errors. Nightmare. I'll put some feelers out tonight on your behalf and see if some of heating engineer contacts have any thoughts.
Buy Bodge Buster – Homeowner Air Source Heat Pump Installation Guide: https://amzn.to/3NVndlU
From Zero to Heat Pump Hero: https://amzn.to/4bWkPFb
Subscribe and follow our Homeowners’ Q&A heat pump podcast
Posted by: @sazHi there,
I an living in a heatpump nightmare at the moment. New ASHP installed last year, endless leaks and pressure drops occuring daily led to repair that involved removal of buffer vessel, PRV and the system being injected with a leak sealer. Then the pump broke down completely with error messages appearing 'compressor blocked/flow rate too low'. Repair people been out to check filter, not that. I have no heating and hot water so was told to use the immersion. It is run via the heat pump power supply and this switch (picture attached). However, I have noticed that the tank temp sensor is dropping, the circulation pump that generally only comes on when heating is being called for is now running constantly (for no purpose because the heatpump cannot provide it at the moment?). Is this pump running cool water through the coil in the tank and cooling the water that the immersion is trying to heat? Help! I am so cold and fed up. (the immersion is not wired in to its own separate supply.
Hi Saz,
Sorry to hear about your problems.
What is the make and model of your heat pump? It may be possible to change the settings within the heat pump controller to stop the water pump from running, and only use the immersion heater.
If the circulation pump that you mention is external to the heat pump, then it may have a plug and socket connection, so can be unplugged. Who is the manufacturer? The circulation pump may be running continuously because the indoor air temperature is low, so the system is continually asking for heating, so the water may be just being pumped around the heat emitters. Try turning the thermostat right down and see if the water pump stops.
Hi Derek,
It's a Vaillant Arotherm plus. The ciculation pump is a Wilo. The UFH is off, and so are the rads, so I don't get why it's even running, the heatpump is not working and I don't understand why the tank temp sensor is not working either, temp doesn't increase when immersion is on, it drops. I can't turn the heat pump off to stop the circulation pump because the immersion power supply runs off it.
Posted by: @sazHi Derek,
It's a Vaillant Arotherm plus. The ciculation pump is a Wilo. The UFH is off, and so are the rads, so I don't get why it's even running, the heatpump is not working and I don't understand why the tank temp sensor is not working either, temp doesn't increase when immersion is on, it drops. I can't turn the heat pump off to stop the circulation pump because the immersion power supply runs off it.
Hi Saz,
Look at the controller fitted to the circulation pump and see is it can simply be switched off. If not, then see if the power supply can be unplugged at the pump controller.
Have two responses. They may not be overly helpful, but I have to agree that you need to get the installers out, despite them not being very good. If you don't want to go down that route, you will have options if they were MCS certified. Were they?
Your other option is to call Vaillant – by all accounts their support team is usually very good.
Response 1:
First thought would be that it's a really bad install and talking to the manufacturer of the heat pump first may put some light on the issues as I would assume the heat pump is still under some kind of warranty.
Loss of pressure and control issues don't help but understanding if the pump has been designed and installed correctly would help.
Response 2:
Well the fact a buffer was present tells you there was issues with flow in the first place, removing will not help.
My advice is get the manufactuer out to check over, complete heat loss and diagnose the issue. Would help to know the installer and manufacturer and we might be able to help using our connnections and reach.
Buy Bodge Buster – Homeowner Air Source Heat Pump Installation Guide: https://amzn.to/3NVndlU
From Zero to Heat Pump Hero: https://amzn.to/4bWkPFb
Subscribe and follow our Homeowners’ Q&A heat pump podcast
@derek-m I've turned the whole system off now as that pump starting to make strange noises and I was getting quite freaked out. This does however mean I have no immersion now so no hot water 🙁
Sounds like a big mistake having leak sealer put into your heat pump. Did you installer do that ?! Surely that's the reason for 'compressor blocked'.
@editor Sorry, I should have said they replaced the buffer but altered some pipework I think. That latest repair has caused the whole system to break down. My immersion is not on it's own power supply so now I have no hot water either. It's just all going from bad to worse! I hope a visit by a senior engineer from Vaillant will at least start to get to the bottom of it as otherwise I think I'm going to crack up. I'm at the point where I feel like I may need to get legal advice but I'm not sure where to go. There are lots of strange things going on with this set up, it's been like it since installation but I have never had any satisfactory answers by the installers.
@heat-pump-newbie Yes, the installer did it. Well-meaning I guess as they were fed up repairing leaks but Vaillant seem to think it's affected the flow rate somehow. I'm not sure what compressor blocked means. It might not mean an actual blockage as such, just that the compressor has been blocked from working due to low flow. I won't know until someone competent looks at it.
Posted by: @heat-pump-newbieSounds like a big mistake having leak sealer put into your heat pump. Did you installer do that ?! Surely that's the reason for 'compressor blocked'.
Hi Newbie,
I suspect that you are probably correct.
- 22 Forums
- 2,048 Topics
- 44.7 K Posts
- 26 Online
- 3,276 Members
Join Us!
Trusted Installers
Struggling to find a reliable heat pump installer? A poor installation can lead to inefficiencies and high running costs. We now connect homeowners with top-rated installers who deliver quality work and excellent service.
✅ Verified, trusted & experienced installers
✅ Nationwide coverage expanding
✅ Special offers available
Latest Posts
-
RE: Hydronic plinth heaters and ASHPs
I have a mitsubishi wall mounted fancoil which is I thi...
By JamesPa , 5 hours ago
-
RE: Renewables & Heat Pumps in the News
Historically, it's been low generation from fossil fuel...
By Transparent , 11 hours ago
-
RE: Additional Battery v Wind Turbine v Ripple
There was a call today for Ripple investors and amongst...
By Judith , 14 hours ago
-
RE: Yes, the "zoning with ASHP" topic again...
Thanks, James — that’s a really encouraging and fair re...
By HarryRea , 15 hours ago
-
@heatgeek I kind of get it… but aren’t you still in the...
By SUNandAIR , 16 hours ago
-
-
RE: Commencing on an ASHP Installation Process
I think you may very well be right and of course A2A ca...
By JamesPa , 1 day ago
-
-
RE: Agile: average import cost vs other tariffs?
@old_scientist We are with SSEN and our G99 application...
By Toodles , 3 days ago
-
RE: Solar Power Output – Let’s Compare Generation Figures
Yes. Storing the solar generation within the home is gr...
By Transparent , 3 days ago
-
RE: ASHP Ecodan L9 error - No Heating but Hot Water
@phoenix15, @heacol cover your area… I’d strongly recom...
By Mars , 3 days ago
-
RE: Warm weather and heat pumps.
@editor Oh nothing right now because $ needed for struc...
By Lucia , 3 days ago
-
RE: Potentially more choice including air to air heat pump grants
@jeff Such documents are far too wordy for my ‘daily re...
By Toodles , 4 days ago
-
RE: Getting the best out of a heat pump - is Homely a possible answer?
@grahaml I cannot agree that it is a small percentage o...
By benson , 4 days ago
-
RE: Samsung Gen6 16kW tribulations
@emceed, can you please give us an update on your syste...
By Mars , 5 days ago
-
What's the problem you are trying to solve. The answer...
By JamesPa , 1 week ago
-
Good luck. For what it is worth my system was very def...
By JamesPa , 1 week ago
-
RE: Massive Electricity Cost for Running My Air Source Heat Pump
I agree @mark-h The Building Regs are now very readable...
By Transparent , 1 week ago
-
RE: Help me understand my Mitsubishi Ecodan system
@carpenterstation When changing settings in the ser...
By RobS , 1 week ago