“During the last few months that I have known James, he has tackled several jobs for me and throughout that time, I have found him to be trustworthy, knowledgeable and reliable. Jon’s have ranged from installing a pressure pump for the mains supply to recommending and replacing a boiler. All tasks were completed efficiently and without fuss. Thank you James and well done!”
Public evidence profile · Checked June 2026
JCM Heating & Plumbing
- Rated 5.0 from 16 reviews
- 12 reviews in the last 12 months
How this score is worked out
How this score is made up
See the independent checks
- Licences and credentials0.6 of 8.3
- Ways to reach them7 of 8.3
- Reviewed on more than one site0 of 6.2
- Registered company details0 of 4.1
- Photos of their work0 of 2.1
- Industry recognition0 of 1
Missing evidence lowers the score because we can't check it. It doesn't mean it doesn't exist. Claiming a profile never changes the score. Evidence context, not a guarantee of workmanship.
What we can verify about JCM Heating & Plumbing
Each card sums up one thing we can check from public sources. Open it for the full detail and the named source. This is evidence context, not a guarantee.
See the full verification checklist for JCM Heating & Plumbing →What customers say
These reviews are published independently on the named public source below, not testimonials this business chose to show. We bring them together and link each one back to where it appeared, so you can open the source and read it yourself.
- Which? Trusted Traders16 reviews · 5.0 avg
Highlights
“James is responsive, reliable, knows what he is doing and his costs are reasonable. My wife and I both liked him. Would definitely recommend.”
“James skilfully installed a new Vaillant boiler, radiators and Megaflow and the system is working perfectly and efficiently. He completed the job on time and came in under the agreed budget. I am very satisfied with the standard of his workmanship and would happily recommend his service.”
Detailed reviews
These are the individual reviews we hold for JCM Heating & Plumbing, including the highlights above. The 16 headline total is the review volume reported across public review sources.
James' workmanship is of the highest standard. I needed a bathroom tap replaced, new garden taps installed, pipework adjusted and a boiler service - he tackled all of it with great efficiency. He also searched thoroughly for suspected water leak in the property and provided a detailed report for me to send to Thames Water. He is a lovely, honest man and pleasure to have around but most importantly his knowledge and professionalism gave me complete confidence in asking him back to replace an old boiler and radiators that I have been putting off until now. He has always responded very quickly to any questions I have had and gone the extra mile to make sure I am happy with everything. A highly reliable and trustworthy tradesman whom I would not hesitate to recommend.
James spent 4 days renovating my downstairs cloakroom in August 2025, fitting a new stopcock, vanity / sink unit, towel radiator and back to wall toilet, followed by a full reset / test of the heating / hot water system. Prior to this in Jan/Feb 2024 he also worked with another Gas Safe Engineer to remove a 1960's hot air heating system (vents / ducts, no radiators etc) from my 3 storey house, and fit new radiators, remove old water tank and fit a combi boiler. Both jobs were done to an excellent standard. He is punctual, well mannered and friendly. My house was a wreck during the first job, but this recent job was the final part of my renovation and my house was finally looking nice! He left everything spotless and tidy after each day's work, cleaning down the floors, sink and toilet to remove dust and disposed of the waste. I cannot recommend James highly enough. I have had mixed experiences with tradespeople over the course of my renovation but James is someone I am very happy to recommend.
I had a slow leak from my toilet cistern. The overflow pipe seal at the bottom had perished and needed replacing. James correctly diagnosed the problem over the phone and was confident it would be a quick repair within his normal callout charge. We agreed a visit time, but he called to see if he could arrive earlier as he'd finished he previous job quickly. He showed me the problem, explained why it happened and what he recommended as a repair - new overflow pipe, with new rubber seal, but also a mastik/glue seal around the inside and outside (because this would last longer than the rubber seal on it's own.) I had to leave the cistern empty overnight to allow the glue to set. The work took around 40minutes and he said I should check I was happy with the work the next day, then let him know if the repair was OK - then he'd either come back or send his invoice.
We suddenly found ourselves with a hammering sound in our old gravity-system water supply, and no running water in our three-storey Victorian house. James Muldowney had been recommended by neighbours. We telephoned him on a Thursday afternoon and he made a special point of coming early on the following Saturday morning. He very efficiently inspected the entire water system, starting with main water tank (empty), detecting a fault in the main tank ball-cock (which he replaced), dismantling the water supply in a lavatory cistern (replacing a faulty part), and testing the entire system before his departure - all in the space of a little over an hour. My wife and I (both in our eighties) were delighted with his work and with the friendly helpful way in which he explained the malfunctions and the reasons for replacing parts that were no longer working as they should. Hugely grateful!
James fixed our dishwasher and was punctual, good customer service.
Read the other 2 detailed reviews on this pageShow fewer reviews
James has done quite lot of work for me, he's changed our water softener, changed over a shower and most recently he's put in a whole new shower. He's always very responsive & good at solving problems. He's willing to work hard, to get good results.
James came to inspect my flat, we had an issue with wet floor whcih was going down into the flat below. He was honest and explained that a job to fix this would be much better done by a wet floor specialist and I appreciated the transparacy. The work he has done for me however, includes servicing and coming to mend problems. His manner is great, you can always rely on him and he is very efficient. I couldnt recommend him more highly.
Rated 5.0, above the local average for plumbers in Isleworth
Across 11 plumbers in Isleworth, the typical rating is 4.7 out of 5. We compare against the same businesses a homeowner would find searching for this trade locally.
Credentials and memberships
These credentials and memberships are attributed to named public sources. Check the source before relying on them.
- Source checked
- 25 Jun 2026
Photos listed on Which? Trusted Traders
These sources do not label every image as completed work. The gallery may include projects, people, logos or certificates, so it does not count as completed-work evidence.
Where this information comes from
Everything on this page is drawn from named public sources. Where a source provides a public link, you can open the original and dig deeper.
Review sources
Public evidence last checked June 2026
About
The business looks forward to speaking with you to discuss your plumbing and heating needs.
Services they list
Listed on public sources or the business's own website; check directly that they cover your job before you book.
About this business
What to check before you hire
Approved plumbers on the free WaterSafe register are vetted, qualified to the water regulations and insured. Check they're listed, or find a WaterSafe-approved plumber near you.
Check the WaterSafe registerWant an extra legitimacy check? Run the Cowboy Checker on JCM Heating & Plumbing before you contact them.
Run Cowboy Checker →Common questions about JCM Heating & Plumbing
Is JCM Heating & Plumbing a legitimate business?
JCM Heating & Plumbing has 16 independent public reviews, rated 5 out of 5. This is independent public evidence gathered from named public sources (no ads, no paid placement), not a guarantee of workmanship. If anything here is out of date, the business can request a correction.
What do customers say about JCM Heating & Plumbing?
JCM Heating & Plumbing has 16 public reviews, averaging 5 out of 5. You can read the individual reviews and where each came from in the reviews section above.
How do I know JCM Heating & Plumbing's reviews are genuine?
JCM Heating & Plumbing's 16 public reviews come from a named public review source, and MyTrustedTraders links every one back to where it was published, so you can open the source and read them yourself rather than trusting a single curated page. MyTrustedTraders brings this public evidence together with no ads and no paid placement: we show where every review came from rather than selling rankings, so you can weigh the evidence for yourself.
Has JCM Heating & Plumbing had recent public reviews?
JCM Heating & Plumbing has 12 public reviews dated within the last 12 months. That shows their review history includes recent feedback; it does not prove current availability, so confirm capacity before hiring.
Is JCM Heating & Plumbing qualified and accredited?
We hold 1 independently sourced credential for JCM Heating & Plumbing, including Which? Trusted Trader. Each is attributed to the body that issued it in the credentials section. For example, Which? Trusted Trader is Which? Trusted Trader: an endorsement from the consumer champion Which?, given to traders who pass its assessment process.
What does JCM Heating & Plumbing specialise in?
JCM Heating & Plumbing lists specialist services including Boiler installation, Boiler repair, Boiler servicing, Gas cooker installation, Gas cooker repair, Gas emergencies. If your job is one of these, look for it in their listed services or ask them to confirm for your project.



