Joining the Renewable Heating Hub forums is completely free and only takes a minute. By registering you’ll be able to ask questions, join discussions, follow topics you’re interested in, bookmark useful threads and receive notifications when someone replies. Non-registered members also do not have access to our AI features. When choosing your username, please note that it cannot be changed later, so we recommend avoiding brand or product names. Before registering, please take a moment to read the Forum Rules & Terms of Use so we can keep the community helpful, respectful and informative for everyone. Thanks for joining!
MCS guidelines and complaints - Ground Source Heat Pump installation and servicing
I have been trying to learn about what standards, guidance, and training the MCS provides for corrosion prevention in GSHP systems, and have not been able to learn anything in the past three months of searching. I also would like to know whether GSHP installers/service providers need to have a Water Regulations Certificate and/or an Unvented Hot Water Certificate for installation, commissioning, and servicing of GSHP - as OFTEC requires as a pre-requesite for anyone who wants to take their GSHP courses.
In order to file a complaint against an MCS-certified installer, one needs to know whether they may be in violation of MCS standards. Or is the MCS missing standards for water quality and corrosion prevention in GSHP (or heat pumps in general)??
Hi @phowardstutterheim - I did spot your post arriving on your other topic this morning, but I was busy trying to resolve an unrelated issue in China.
There may be others here who know/understand the regulations for GSHPs and MCS approved installations.
But in the meantime, could you give us any better idea of what sort of water you have in your location?
I grew up in Wiltshire (think - chalk steams) and now live in West Devon (granite & soft water).
So I appreciate the widespread differences in water types which are geographically imposed.
Save energy... recycle electrons!
Posted by: @phowardstutterheimI have been trying to learn about what standards, guidance, and training the MCS provides for corrosion prevention in GSHP systems, and have not been able to learn anything in the past three months of searching. I also would like to know whether GSHP installers/service providers need to have a Water Regulations Certificate and/or an Unvented Hot Water Certificate for installation, commissioning, and servicing of GSHP - as OFTEC requires as a pre-requesite for anyone who wants to take their GSHP courses.
In order to file a complaint against an MCS-certified installer, one needs to know whether they may be in violation of MCS standards. Or is the MCS missing standards for water quality and corrosion prevention in GSHP (or heat pumps in general)??
If you have not already done so, I would suggest that you get the water analysed to see what may be causing the corrosion.
Have done/am doing so, via Hydratech - https://www.hydratech.co.uk/fluid-testing-and-analysis-closed-loop-systems
They found no inhibitors in the hot water side, and the pH was 6.
They are analysing the refrigerant side now. Yesterday, my husband measured a pH of 6, Brix = 15.5 (polypropylene glycol content = 20% 2/2 or 19.4% v/v, and small particles are present - when exposed to oxygen, the water turned rust colour.
Apparently, only MCS-certified installers have full access to the standards?
Our mains water quality is fine - just on the hard side. Water analysis found no scaling in our system, no biological contamination on the hot water side. We just installed a Sorbox filtration system that supposedly takes care of everything - but not in time to prevent a lot of corrosion that has already occurred. We want to know what our installer/service company were trained / told they should do to prevent this.
Posted by: @phowardstutterheim
Have done/am doing so, via Hydratech - https://www.hydratech.co.uk/fluid-testing-and-analysis-closed-loop-systems
They found no inhibitors in the hot water side, and the pH was 6.
They are analysing the refrigerant side now. Yesterday, my husband measured a pH of 6, Brix = 15.5 (polypropylene glycol content = 20% 2/2 or 19.4% v/v, and small particles are present - when exposed to oxygen, the water turned rust colour.
Apparently, only MCS-certified installers have full access to the standards?
So the brine is acidic.
pH isn't high enough.
I'm unsure whether system inhibitor would've been adequate to raise it.
I would expect it should be lying between 7.3 - 7.8
Save energy... recycle electrons!
- 26 Forums
- 2,618 Topics
- 61.1 K Posts
- 860 Online
- 6,994 Members
Join Us!
Worth Watching
Latest Posts
-
RE: Renewables & Heat Pumps in the News
An article on funding for heat pumps in case anyone is ...
By Jeff , 2 hours ago
-
RE: Indevolt Batteries UK Support & Info Thread
Thanks @editor , @indevolt-uk Subject to any comments ...
By JamesPa , 10 hours ago
-
RE: Share Your Experiences with Heat Pump Manufacturer Support
@seoras Sorry to hear that. I found Vaillant very help...
By JamesPa , 10 hours ago
-
The Watchdog That Watched and Waited
On 9 January 2026, Consumer Energy Solutions collapsed ...
By Mars , 14 hours ago
-
RE: GSHP Kaput After 16 Years: New Compressor or Switch to ASHP? Advice Welcome
Cool Energy in Grimsby sell ground source heat pumps an...
By DerekDeLeon , 14 hours ago
-
RE: Valliant Heat Pump Settings
Thats arguably a sign of a good installer - they unders...
By JamesPa , 15 hours ago
-
RE: Electricity price predictions
Well, we have so many cases where rain water mixes with...
By Batpred , 16 hours ago
-
RE: Two heating zones to one zone
@profzarkov They arent obviously wrong, but the only...
By JamesPa , 18 hours ago
-
RE: Towns water feed to air source heat pump system
The DHW circuit cant be separated (well it could, you c...
By JamesPa , 18 hours ago
-
Solis AC-coupled 3kW storage inverter
Solis AC-coupled 3kW storage inverterPylontech batterie...
By MartinRobinson , 24 hours ago
-
RE: My NIBE ASHP Nightmare: No Commissioning, High Bills and a Hostile Installer
As @transparent has observed above, this is not bad, an...
By cathodeRay , 1 day ago
-
RE: The Grid Says Yes.. Until It Doesn’t: Why Britain's Net Zero Push is Stalling at the Plug Socket
As I was reading this article Mars, I was thinking that...
By Toodles , 2 days ago
-
RE: Tell us about your Solar (PV) setup
Installed in May 2011: 16*Sharp 245 W monocrystalline p...
By txmartyn , 2 days ago
-
-
RE: Say hello and introduce yourself
That doesn't sound 'right' to me. The national Smart ...
By Transparent , 3 days ago
-
RE: Growatt battery disconnected
I doubt this will happen, but I will try and suggest it...
By Eliuccio , 3 days ago
-
Understood. That's why I decided from the outset on a ...
By JamesPa , 4 days ago
-
RE: My experience with 3 heat pump surveys: Heat Geek, British Gas & Octopus
On the litigation, I would not go there and definitely ...
By Batpred , 4 days ago
-
RE: Recommended home battery inverters + regulatory matters - help requested
I suppose if your pv inverter packs up, you have a plan...
By Batpred , 4 days ago
-
RE: New Vaillant aroTherm Plus in black - When will it come to the UK?
Firstly check you are using sound power not sound press...
By JamesPa , 4 days ago
-
That’s the solar up and running, I don’t think it’s the...
By David999 , 4 days ago
-
RE: Seeking ideas / information / commiseration - Pure Drive
I agree with @colinc that you can reuse some of it. A s...
By Batpred , 4 days ago
-
RE: Solar Power Output – Let’s Compare Generation Figures
@toodles Im trying me best to ignore orangeman, I figur...
By Papahuhu , 5 days ago



