Vaillant UK Reviews 

Very friendly and patient service (from engineer #567) , lots of information and effort put in with attention to things that could save us trouble in future.

Had a problem with our boiler. The engineer, #252 was fantastic… charming, helpful and incredibly professional.
Thank you

had my vaillant boiler repaired yesterday by Ben151.
he explained the fault he found and the steps he was taking clearly to me and acted in a very professional manner.

Our combi boiler (Vaillant ecotec pro 35) suffered a number of under warranty CO sensor failures which required multiple visits from Vaillant engineers to sort out the problem. The need for repeated visits became an irritation so I upscaled by concerns with Vaillant and requested a permanent solution to the problem. Within a week of my complaint a visit from a senior engineer was arranged with a view to the replacing the boiler. This was agreed and one week later the engineers fitted the new boiler free of charge.
Though I was frustrated with the CO sensor failures I am impressed with both Vaillant customer services and engineers who treated our case promptly and efficiently. Within two weeks of my original email I now have a new Vaillant boiler. If only all companies acted so empathetically and promptly!

Gary is the Vaillant engineer who covers our area. He's a nice guy and knows his stuff so does any repairs or servicing needed efficiently and effectively.

Everything repaired in next to no time. Very satisfied with the service Valiant provided.

Reported a problem at approximately 8:30am and was notified that Josh, an engineer, would be with us during the day. He arrived at 2:15pm and sorted everything out within an hour. Excellent service from the engineer and indeed Vaillant as a whole. Would definitely recommend the company, their products and their service.

I have a three year old Vaillant ecoTEC plus 637 that is under warranty. When you ring Vaillant to get a repair they make it as difficult as possible to actually get someone out. Apparently there has to be a guaranteed parking space within 100 yards of the property and it has to be available when they turn up (all day appointment by the way) otherwise they will charge you £99 for a failed appointment. I live in central London, there are parking spaces everywhere but apparently Vaillant are unable to drive around and find one like everyone else. They also have to physically see the boiler comissioning checklist and service record, photo or scan is not good enough.
As I can't gurantee there will be a free parking space within 100 yards at the time of arrival I have had to pay for a gas engineer to attend and repair even though the boiler is under warranty. WHAT A SCAM

Good tutors - interesting and engaging atmosphere. 🛠️👍

Very poor indeed. New boiler fitted in 2023 repair required last year .still under warranty so Vaillant Engineer attended drained the system and left tenants with no heating or hot water in mid winter. Failed to return when agreed forcing me to employ local plumber to do repair. A ridiculous excuse about the PH being wrong when the system had been drained was later withdrawn as a “mistake”By this time tenants have moved to a hotel.
Vaillant offered a paltry £100 off the £400 bill hiding behind restrictive terms of the warranty. All reported to the CEO who failed to correct his colleagues failings.
The boiler has just failed again and this time it’s beyond repair- a leaking weld on the heat exchanger. The local plumber will now have nothing to do with Vaillant citing poor reliability and warranty difficulties on numerous occasions. Having to get a new boiler which definitely won’t be a Vaillant.
I would strongly advise anyone considering a boiler installation not to consider a Vaillant.
In contrast at another property we have 2 Ideal Standard Classics which are now 23 years old - they have required minimal repairs are far more robust-the parts are cheap and readily available. Any theoretical “efficiency” associated with Vaillant products is more than outweighed by their terrible unreliability and failure to stand by their brand.
PS Vaillant have just emailed me confirming that I accepted the £100 offer they made last year in full and final settlement - as if that changes anything. At the time I explained in writing that I was only accepting this derisory offer because I had no alternative. Unfortunately this response from Vaillant confirms a consistent refusal to actually engage on the real issue.. I stand by every word of the review and you will note that most of my Trustpilot reviews are positive.

The engineers arrived on time, understood the problem and were able to resolve it on site. They were v helpful and explained the issues to us clearly. They liaised with the system fitters too.
Excellent service
Thank you

Our Vaillant engineer Richard (No 146) could not have been more helpful or informative. His knowledge of our heat pump system was exceptional and he managed to answer all our questions in a very easy to understand way - which as pensioners was a huge help!
We have always had Vaillant gas boilers in the past and now we have an air source heat pump. Their product and aftercare is still the best so we will definitely remain loyal customers.
Thank you Richard and thank you Vaillant.

Won't know until Winter time, the DHW works great now. This replaced a Glowworm installed 1985. The instructions I find are as informative as a bus ticket or as comprehensive as a Thesaurus with nothing in between. Maybe it's me but I don't find it user friendly, it's very complex. Maybe all modern ones are. Just saying.
Fantastic installation, looks great, I'm very happy with it.

Tom (538), from Vaillent did an annual boiler service today. He was totally efficient and very pleasant to deal with. Would definitely recommend Vaillent for their level of service and for turning up on time and on the arranged date with no issues.

The engineer rang me prior to his visit to let me know when he would be arriving. He was very efficient and speedy at fixing the problem with my boiler. He was very pleasant and helpful when in my property. The problem with my boiler had been ongoing since November. He had fixed it in 45 minutes, a great service.

Vaillant can't be trusted to honor the system capabilities that they advertise. Their internet gateway, essential for accessing your heating controls via a smart home system such as Alexa is currently advertised as having Alexa control, not an unusual thing in 2026. Vaillant have removed this functionality with no apparent intention of restoring it, but are still happily advertising it as a function in their sales literature. This is deceitful, don't expect anything that they advertise to be true.

Engineer was very friendly,helpful and kept me informed what he was doing

The engineer, a friendly chap turned up on time and explained the work that was done.

Engineer arrived on the same day I called and fixed the fault. Engineer was thirough, respectful of my property and explained what he was doing and why.