Vaillant 10kw ASHP installation. Installer issues
Hi all,
Sharing my experience and current heat pump situation to potentially get some input and advice.
Had a 10kw vaillant installation which I am now concerned about due to the following issues;
The pump has been identified as oversized for my property
The installer recommended the 10kw heat pump based on my previous bills and did not carry out a heat loss calculation for the property. is this correct?
He originally suggested a 7.5kw but when I queried if the pump will provide sufficient hot water and heating, the installer recommended the 10kw saying it was a slight increase in price which will definitely provide the required heat. I later found out he should have advised otherwise using his professional knowledge but didn’t.
I was quoted for items that were not installed most importantly I was quoted and advised that a buffer tank will be installed however upon installation, a low loss header was installed. Upon review by another heat engineer at cost to me, I was advised that the system would perform better with the buffer tank due to the size of the heat pump especially given that it’s oversized for the property.
The pipes were not insulated leading to heat loss.
installer damaged property during installation and is yet to rectify the issues
The heat pump appears to require planning permission due to size but I was not advised of this by installer
The heat pump is noisy and also drains water into the drive which then freezes up.
The issues above have been identified however, I have been trying to get the installer to rectify these issues and they have been very bullish and a bit intimidating while also giving misleading information. Originally insisting they would not rectify the issues and involved vaillant.
Given their behaviour, I advised of my intention to raise a dispute with RECC which they claimed to be a member of. I have now found out that they are not a member of RECC, it is a different company with the same director that is RECC member. It is the director that I have been dealing with. I feel that I’ve been misled by this company and I could have serious issues in future in addition to the issue with their workmanship. I’m really not sure what to do. To escalate, I could raise the issue with RECC against the member company but my contract is in a different company name????
Quite honestly, this kind of installer behavior has to come to an end. It’s nuts.
There are clearly some basic issues, like drainage and damage. The buffer is a contentious subject, so one to avoid for now. And yes, a heat loss calculation should have been carried out to size the heat pump correctly.
The RECC angle is one worth pursuing, but I’ve yet to encounter an homeowner that has received a positive outcome. But I keep forwarding them cases, trying to add pressure.
Are any of the installers MCS certified? Also, have you paid them yet? If you haven’t, don’t pay until the matter is resolved.
Buy Bodge Buster – Homeowner Air Source Heat Pump Installation Guide: https://amzn.to/3NVndlU
Follow our sustainability journey at My Home Farm: https://myhomefarm.co.uk
@editor thanks for this. Yes I will pursue the RECC and see what comes of it. Well the MCS certification is held by the sister company which is the same one with RECC registration. It’s the sister company that also applied for the BUS scheme .
I will explore raising with MCS too
How concerned should I be about the drainage? The reviewing heat engineer mentioned the drainage and I’ve also seen posts about the drainage here.
Well I am pursuing the buffer on two basis, one- that’s what I was quoted and it was changed without an approval or advise to me, two -the buffer is more suited to the pump size as explained to me. Although I was also advised that the pump is powerful enough to work without the buffer and llh, the buffer is the better of the two for the installation. The buffer can hold more volume of water to help the pump work efficiently without needing it to kickstart so frequently as it does now leading to high energy use. It will be marginally better but still better and I believe it will help the lifespan of the Heatpump too.
Thank you for confirming that a heat loss calc was necessary. When I asked the installer about this and the information they based the hp size recommendation on, they simply sent my bills and claimed that was enough to make the recommendation. I requested a heat loss report from another engineer and I know my installer definitely didn’t provide this. They seem unaware of the significance of this report . They did check the ECS of the building though. Could they claim this is enough and replaces the calculations?
There is an outstanding balance which I am currently using as leverage. If I had paid everything, I would be in a much worse situation right now. It is only leverage though as if they do not fix the issues, it will cost me potentially more than the balance to fix their mess. I intend to have all the issues resolved before paying the balance and I’ve informed the installer of this.
providing you have compensation controls (ie not heat miser, nest, hive, honeywell) from the heat pump manufacturer and providing system volume is within heat pump manufacturers specification the lack of buffer is not an issue.
Over sizing is disappointing, but what is the actual heat loss? How many radiators?
If MCS is behind this then how come a heat loss calculation was not undertaken? But you also need to appreciate heat loss calculations are only skilled guessing as you don’t know the building fabric and ventilation of an existing building in its entirety
At the end of the day a heat pump is just another heat source. It doesn’t really need a heat loss calculation to work effectively.
is the lack of insulation indoors or outdoors?
If you didn’t ask him to get planning permission specifically it’s not really his issue (MCS may suggest otherwise)
Professional installer
Posted by: @gemiar@editor thanks for this. Yes I will pursue the RECC and see what comes of it. Well the MCS certification is held by the sister company which is the same one with RECC registration. It’s the sister company that also applied for the BUS scheme .
I will explore raising with MCS too
How concerned should I be about the drainage? The reviewing heat engineer mentioned the drainage and I’ve also seen posts about the drainage here.
Well I am pursuing the buffer on two basis, one- that’s what I was quoted and it was changed without an approval or advise to me, two -the buffer is more suited to the pump size as explained to me. Although I was also advised that the pump is powerful enough to work without the buffer and llh, the buffer is the better of the two for the installation. The buffer can hold more volume of water to help the pump work efficiently without needing it to kickstart so frequently as it does now leading to high energy use. It will be marginally better but still better and I believe it will help the lifespan of the Heatpump too.
Thank you for confirming that a heat loss calc was necessary. When I asked the installer about this and the information they based the hp size recommendation on, they simply sent my bills and claimed that was enough to make the recommendation. I requested a heat loss report from another engineer and I know my installer definitely didn’t provide this. They seem unaware of the significance of this report . They did check the ECS of the building though. Could they claim this is enough and replaces the calculations?
There is an outstanding balance which I am currently using as leverage. If I had paid everything, I would be in a much worse situation right now. It is only leverage though as if they do not fix the issues, it will cost me potentially more than the balance to fix their mess. I intend to have all the issues resolved before paying the balance and I’ve informed the installer of this.
Vaillant produce schematics without a buffer, and are perfectly happy without one “ providing system volume is big enough” and you don’t use on off controls
Professional installer
Don’t pay them the balance, run them off the job, find someone else to fix this mess.
They seem like proper cowboys these ones.
You could find any competent plumber, give them the manufacturers installation schematic (not the one from the merchant, or from some third party) that suits your system and tell them to get in with it.
The manufacturers produce these for a reason. Choose the one without any hydraulic separation for the best system efficiency.
As for the planning issue… if anyone asks, tell them it’s an air conditioner 😉
A heat loss calc isn’t technically necessary if you know that the property is adequately heated by the current boiler. I’d argue that rad sizing to rooms at a lower flow rate is more important. For example, my place has an 11kW baxi Bermuda, installed when the property had no loft insulation and no double glazing, it managed to heat the place just fine back then, and still does now. So you could just say 11kW is fine and be done with it.
Off grid on the isle of purbeck
2.4kW solar, 15kWh Seplos Mason, Outback power systems 3kW inverter/charger, solid fuel heating with air/air for shoulder months, 10 acres of heathland/woods.
My wife’s house: 1946 3 bed end of terrace in Somerset, ASHP with rads + UFH, triple glazed, retrofit IWI in troublesome rooms, small rear extension.
Posted by: @gemiarHow concerned should I be about the drainage? The reviewing heat engineer mentioned the drainage and I’ve also seen posts about the drainage here.
I think it depends where your pump is. Our condensation drainpipe froze over in the cold and the pump slowly dribbled water across the paving from under it, which then froze, but we don't use that path much when it's that cold, there was space to step over it and it slopes away from the house, so I'm not bothered enough to change the drain (wider-diameter pipe or steeper fall).
Oversize unit: it may cycle in and off more on low output, as the heating load might be below the minimum turn down capacity of the unit. That will cost more in the longer run as cyclic operation consumes more power than steady state inverter control. If the ASHP is not massively oversized it won't be significant.
Drainage: it's not difficult to connect the unit drain to a soak-away under or adjacent to the unit. If the unit is on concrete pad or paving, core cut through this to the hardcore underneath, which is unlikely to ever have a penetrating ground frost. Condensate is pure water, so connection to either a permanent drain or a soakaway is possible. Drain pipe as short as possible and insulated, should not require trace heating that way.
Planning: Your personal choice, but planning responsibility is vested with the homeowner not the installer. I would seek retrospective planning permission as, if you ever want to sell your property, the lack of planning permission will surface in conveyancing and you may be obliged to either take indemnity out on behalf of the buyer or address the issue then. The Local Authority is very unlikely to refuse permission for ASHP if unit volume >0.6m3 is the only material planning issue. You might need to submit a completed MCS noise level assessment to prove noise level compliance 42.0dB(A) max at adjacent dwellings if relevant.
Heat Load Calculations: Essential? I would say so. Both to size the overall unit and, more importantly, to check individual room emitter sizing and capacities. For underfloor heating room emitter is less critical, because you have a very large surface area. But for retrofits where ASHP is married to wet radiators, the existing rads need to be checked and, often, increased in size to suit the lowest flow design temperature possible/practical for the room design temperature. Money spent increasing radiator sizes for lowest design flow temperature will be recouped several fold over the the life of the ASHP in lower electricity consumption due to higher SCOP.
@alec-morrow heat loss from subsequent survey is 5.35kw. Note that the installer originally suggested a 7kw heat pump but wasn’t confident about this recommendation when I queried if that’ll be sufficient for the property hence why he suggested 10kw.
I specifically didn’t want to change the radiators at the time so I’m not complaining about that as it was my choice.
The pipes without insulation are inside the building. The pipes outside are insulated although not very well but they are.
Posted by: @hughfDon’t pay them the balance, run them off the job, find someone else to fix this mess.
They seem like proper cowboys these ones.
You could find any competent plumber, give them the manufacturers installation schematic (not the one from the merchant, or from some third party) that suits your system and tell them to get in with it.
The manufacturers produce these for a reason. Choose the one without any hydraulic separation for the best system efficiency.
As for the planning issue… if anyone asks, tell them it’s an air conditioner 😉
A heat loss calc isn’t technically necessary if you know that the property is adequately heated by the current boiler. I’d argue that rad sizing to rooms at a lower flow rate is more important. For example, my place has an 11kW baxi Bermuda, installed when the property had no loft insulation and no double glazing, it managed to heat the place just fine back then, and still does now. So you could just say 11kW is fine and be done with it.
who is a competent plumber though? At this stage all plumbers are competent until things go wrong. Makes me want to stick to the devil I know and give them the opportunity to fix the issues plus it gets complicated with warranties etc
Posted by: @allyfishOversize unit: it may cycle in and off more on low output, as the heating load might be below the minimum turn down capacity of the unit. That will cost more in the longer run as cyclic operation consumes more power than steady state inverter control. If the ASHP is not massively oversized it won't be significant.
Drainage: it's not difficult to connect the unit drain to a soak-away under or adjacent to the unit. If the unit is on concrete pad or paving, core cut through this to the hardcore underneath, which is unlikely to ever have a penetrating ground frost. Condensate is pure water, so connection to either a permanent drain or a soakaway is possible. Drain pipe as short as possible and insulated, should not require trace heating that way.
Planning: Your personal choice, but planning responsibility is vested with the homeowner not the installer. I would seek retrospective planning permission as, if you ever want to sell your property, the lack of planning permission will surface in conveyancing and you may be obliged to either take indemnity out on behalf of the buyer or address the issue then. The Local Authority is very unlikely to refuse permission for ASHP if unit volume >0.6m3 is the only material planning issue. You might need to submit a completed MCS noise level assessment to prove noise level compliance 42.0dB(A) max at adjacent dwellings if relevant.
Heat Load Calculations: Essential? I would say so. Both to size the overall unit and, more importantly, to check individual room emitter sizing and capacities. For underfloor heating room emitter is less critical, because you have a very large surface area. But for retrofits where ASHP is married to wet radiators, the existing rads need to be checked and, often, increased in size to suit the lowest flow design temperature possible/practical for the room design temperature. Money spent increasing radiator sizes for lowest design flow temperature will be recouped several fold over the the life of the ASHP in lower electricity consumption due to higher SCOP.
You are right - the unit does cycle on and off frequently. The unit is definitely oversized and if that unit size is being installed in the appropriate house, a buffer will accompany to run efficiently
Thanks I will explore this option. The unit drains onto hard ground and we generally don’t walk there except to check the pump.
Understand that planning is a personal choice though the installer should have advised on this. I’m already getting in touch with the LPA to see what is required and they have asked for installation design which the installer has not provided. Also yes it’s the unit volume that seems to be the only issue. Unit runs quietly on normal days but was audible when temperatures dropped to -5
I will be changing the radiators at some point but need the unit to be installed and working as a 10kw vaillant should do first.
-
Viessmann Vitocal 250-A in the UK
2 weeks ago
-
Rate the quality of your heat pump design and installation
3 weeks ago
-
Mid terrace - ASHP Install location
2 months ago
-
Volumiser placement in Vaillant Arotherm + system?
2 months ago
-
Any installer recommendations for Samsung ASHP?
2 months ago
- 25 Forums
- 1,435 Topics
- 30.1 K Posts
- 21 Online
- 1,218 Members
Join Us!
Latest Posts
-
RE: Jokes and fun posts about heat pumps and renewables
@editor To help with your study of Entropy, you may f...
By Derek M , 7 hours ago
-
Are You Getting the Most Out of Your Renewable Energy?
This article is aimed at you if you have recently taken...
By Majordennisbloodnok , 9 hours ago
-
RE: Insulation of flow and return Heat Pump piping
@toodles undesirable but insignificant sums it up prett...
By dr_dongle , 10 hours ago
-
RE: Incorrect Billing of Customers with a Smart Meter
@transparent not sure I’d call SMETS2 a bed rock, as it...
By matmbl , 11 hours ago
-
It is certainly possible, using a modbus connection. If...
By cathodeRay , 22 hours ago
-
RE: Home energy storage & battery register
1 x Seplos 14.3kWh (Seplos box from Alibaba, battery ce...
By KoRWraith , 1 day ago
-
I did another reconnection/ reconfiguration session wit...
By Abernyte , 2 days ago
-
RE: Recommended ASHP installers in Hampshire
@benson After my initial enquiries with Octopus, we had...
By Toodles , 2 days ago
-
RE: Air source heat pump roll call
To help bolster the rather small number of NIBE owners ...
By Steve D , 2 days ago
-
RE: A beginner's journey into DIY home energy storage - no solar!
@editor All good here! I'm happy to say that the system...
By KoRWraith , 2 days ago
-
RE: Say hello and introduce yourself
@fse_bec welcome to the forums, and it’s very generous ...
By Mars , 2 days ago
-
RE: Meter Readings - What are theses meters telling me?
@transparent Hi, I am the landlord of the property, we ...
By Potatoman , 2 days ago
-
RE: Octopus (the grid) is my battery
@andris My ‘Best Effort’ so far was on 4th. June 2023 w...
By Toodles , 3 days ago
-
Save the Energy Save the World using Daikin Altherma 3 operation mode and schedules settings.
Hello Everyone. Our Daikin Altherma 3 was set to Dome...
By Mevl , 3 days ago
-
RE: Have Octopus Energy discovered a way to Narnia?
Oh dear. Always winter never Christmas?
By Davesoa , 3 days ago
-
RE: Bivalent oil boiler system to work alongside ground or water source heat pump
I can provide a lot of detail on LED lighting. But no...
By Transparent , 3 days ago
-
RE: Making best use of Agile with a battery and ASHP
I try to ovoid doing that...
By Majordennisbloodnok , 3 days ago
-
RE: Is this a bad installation and is there something wrong with my Samsung heat pump?
@kenbone no need for what kenbone regarding the 100watt...
By David999 , 5 days ago
-
RE: Bivalent (or even trivalent!) system design options for a new GSHP installation
For your interest @algienon this is what happens when a...
By Transparent , 6 days ago
-
RE: Rising Damp – Production Recommendation
Yet another topic I'm not an expert in. Nonetheless, th...
By Majordennisbloodnok , 6 days ago
Latest Topics
-
Incorrect Billing of Customers with a Smart Meter
By KoRWraith 2 days ago
-
Home energy storage & battery register
By Mars 2 days ago
-
Meter Readings - What are theses meters telling me?
By Potatoman 3 days ago
-
Have Octopus Energy discovered a way to Narnia?
By Davesoa 4 days ago
-
Making best use of Agile with a battery and ASHP
By jamesw 5 days ago
-
By Toodles 7 days ago
-
By Blaine_t 7 days ago
-
Insulation of flow and return Heat Pump piping
By Toodles 7 days ago