# Certified Group Ltd Certified Group Ltd is a plumber in London. Rated 4.9/5 from 394 public reviews across 3 review sources. This is the MyTrustedTraders public-evidence profile for this trader, with independent reviews, credentials and registry data from named public sources, no ads, and no paid placement. No Trust Score yet: review caution: one or more review signals need a closer check. Independent sources agree they've been operating since at least 2012. That's 14 years, confirmed across 2 separate sources. We cross-checked Companies House: this business is officially registered for work that matches the plumber services it advertises - independent confirmation it's a genuine business set up to do this kind of work, not just a directory entry. 6 reviews in the last 12 months. ## About Builder in London. ## Public review evidence (by source) | Source | Average rating | Reviews | | --- | --- | --- | | Checkatrade | 4.9/5 | 254 | | Which? Trusted Traders | 5.0/5 | 135 | | Rated People | 5.0/5 | 5 | _Per-source review counts may overlap. They need not sum to the 394 cross-checked total above._ ## Review signals to check _One or more review signals need a manual check. Some review signals are flagged for a closer manual check. That doesn't prove fake reviews or any wrongdoing._ - **Repeated review text:** 4 exact and 5 similar review-text pattern(s) found across sources Independently rated 4.9–5.0 out of 5 across 3 separate review sources. Ratings that agree across independent sources are far harder to fake than a single glowing profile. Rated 4.9, in line with the local average for plumbers in London. Across 1383 plumbers in London, the typical rating is 4.9 out of 5. We compare against the same businesses a homeowner would find searching for this trade locally. Most recent review: 4 months ago. ## What customers consistently praise _Themes mentioned across this trader's own public reviews:_ - Friendly & polite (mentioned in 35% of reviews we've read) - Professional (mentioned in 27% of reviews we've read) ## Often reviewed for _Job types repeatedly named in this trader's own public reviews:_ - Boiler & heating (6 reviews) ## In customers' own words _Verbatim quotes from this trader's public reviews, each attributed to its source:_ > "Really impressed with the service from Aziz. He was quick to respond, turned up bang on time, and got everything sorted very efficiently with no fuss. He was very professional throughout, and what I really appreciated was that he even called me beforehand to talk me through what to do when he couldn’t get there straight away. Would definitely use again and recommend." > Source: Customer (5.0, via Checkatrade) > "Aziz and Chris are outstanding. They are so thorough with their work and everything is completed to an extremely high standard. They are both lovely people and a pleasure to have in the house. They are very punctual and excellent at communicating. We are so grateful to them for repairing various plumbing issues and they will be our first port of call for anything in the future." > Source: Lucy B (5.0, via Checkatrade) > "Aziz and Chris did a fantastic work of installing a new boiling and heating system in our apartment. Certified Group agreed to take this installation work in a very short notice and that too in the end of October just ahead of winter season which is highly anticipated. They managed to effectively complete the installation in 5 working days which involved dismantling existing boiling and heating system, procuring materials for installing new system, providing demo of the new system. Both Aziz and Chris had great knowledge and skill and were experts in this installation. Highly recommended!" > Source: Customer (5.0, via Checkatrade) ## Trades Plumber, Builder, Carpenter, Concrete contractor, Demolition contractor, Gas Engineer, Handyman, Roofer ## Services they list _Listed on public sources or the business's own website; check directly that they cover your job before you book:_ - Basement / Cellar Conversions - Bathroom & Kitchen Plumbing - Blocked Baths - Blocked Sinks - Blocked Toilets - Brick / Concrete Structural Repairs - Concreting - Demolition - Extensions / Conversions - Fire and Flood Renovation - Foundations - Garage Conversions ## Areas covered _Towns and areas this trader lists serving. This is their own stated coverage, so confirm they cover your exact address before you book:_ - London ## What we checked, and when As of 29 Jul 2026, we hold 394 independent reviews across Checkatrade, Which? Trusted Traders and Rated People for this business, and Companies House lists Certified Group Ltd (no. 08267973) as active, checked 20 May 2026. _What MyTrustedTraders independently checked for this business (verified items only):_ - Review volume: MyTrustedTraders shows 394 public reviews on this profile. (via MyTrustedTraders public listing) - Public listing spread: MyTrustedTraders shows 4 public listings for this trader. (via MyTrustedTraders public listing) - Business identity: MyTrustedTraders shows public business identity data for company number 08267973 with operating status active. (via MyTrustedTraders public listing) - Contact phone: MyTrustedTraders shows a public phone contact on this profile. (via MyTrustedTraders public listing) - Website: MyTrustedTraders shows a public website for this trader. (via MyTrustedTraders public listing) - Trade-specific register: MyTrustedTraders shows Gas Safe Register evidence on this profile. (via Public credential evidence) - Current credentials shown: MyTrustedTraders shows 1 current credential on this profile. (via Public credential evidence) Full verification checklist: https://mytrustedtraders.com/traders/certified-group-ltd-3/checks ## Credentials & sources - Credentials shown: 4 (1 currently verifiable, listed below) - Gas Safe Register: the UK's official gas register. By law, anyone working on your gas appliances must be on it - Companies House status: Active - Website online since 2012 (verified via public domain registry) - Evidence held from: Which? Trusted Traders, Checkatrade, Rated People, Gas Safe Register, TrustMark, WaterSafe, Companies House - Check dates vary by source. Where we hold a date, the check shows it. ## Before you hire a plumber _What to check when choosing this kind of trade (general guidance, not a claim about this business):_ - Agree the call-out fee, the hourly or fixed rate, and whether parts are charged on top, in writing, before an emergency plumber starts. Out-of-hours overcharging and 'while I'm here' add-ons are common complaints. - Be wary of a plumber who, on a first visit, says your whole system or boiler must be replaced. Get a second opinion and an itemised quote (parts and labour separately) before agreeing to major work. - Gas and boiler work is a separate, regulated trade, not general plumbing. Make sure anyone working on a gas appliance is specifically registered to do gas work, and ask to see that registration before they start. - For the water-regulations side of plumbing, a WaterSafe-approved plumber is vetted, qualified to the water regulations and insured. You can check yours or find one free at watersafe.org.uk. - Ask to see a portfolio of completed work like yours, plus recent references you can contact. ## Contact - Phone: 07307 204158 - Website: http://www.certifiedgasheating.co.uk --- Source: MyTrustedTraders, https://mytrustedtraders.com/traders/certified-group-ltd-3 Real public evidence only: every figure traces to a named source and is cross-checked. If a source does not carry a field, it is not shown.