Navien UK Avis 

This is my second review of Navien, both times, exceptional service. Just had Craig drive and hour and a half to get to me, sorted the issue, taught me a few things to keep me going and off he went, leaving me with a warm house again! And the issue wasn't the boiler itself, just something I must have done accidentally. Thanks Craig, total pro.

Please! Please!! Please!!, DO NOT waste your money in this rubbish product and guaranty ad they NEVER works.

If I read all their comments before I would not buy this rubbish but made a huge mistake buying it!

Installed it in 2023 and almost every six months had some issues.

No engineers out despite numbers phone call no complaint procedure available.
No hot water and heaters in tenanted home. I had to buy five oil heaters as there is no guarantee when their engineer will visit and fix the issue. Also they did not allow me to use local engineers to fix under the warranty.

We bought our Navien boiler 2 years ago and on 11 December 2025, in the evening, it broke down. We called Navien rhe following day and were advised that the engineer would come the following week on Tuesday. The technical dept also confirmed on the phone that the problem was the 3 way valve. Two engineers turned up on Tue (waited for them all day as the company cannot offer an exact visit time), had a look and said they didn't have the part that needed to be replaced as they used the last one a day before. On Wednesday we called Customer Service again and were told the part was only ordered on Tuesday even if Technical dept confirmed the fault from the first call. Then silence. On Thursday we called them again. We were told this time that the part was ordered on Wednesday. Customer Service can't check when the engineer visits are scheduled, they can't reach the engineers on the phone, only leave voice messages. We have a kid and a sick person in the house and nobody seems to care. No manager to talk to, just emails. We were also told that the normal warranty is not an emergency warranty for which you need to pay extra. I would like to remind this Navien company that a warranty is a warranty and they need to offer what they promise to offer. Otherwise don't offer it at all and we'll buy something else. This is a disgusting service and a disgusting product that already broke down after only 2 years of use. The engineers who came confirmed that this part is a weakness of this product but Navien still doesn't store pumps, despite them breaking down frequently, and prefers to let their customers freeze than to prevent such disgusting situations.

Fault reported online immediately then on opening of customer service Monday morning. No reply until 4pm. Engineer visit two days later. 2 engineer visits later still faulty. No heating or hot water for 5 days with 2 kids at home. One of which disabled. Numerous calls, reported manager would call back. Emailed complaints team. No response. Poor communication and customer service throughout. Would not recommend in any circumstance. Expensive equipment, poor after care. Need to do better!

Regarding below reply from Navien… have already emailed service email and was assured this would be looked at as priority…. 8 days later… no response!

The technical department were quite happy to leave us with no heating by not telling us how to reconnect our Smart Tok time clock to the point my Boiler is only 12 months old. I am thinking of replacing it already with a different make and definitely not Navien unfortunately I have recommended this Boiler to lots of people big bad mistake as now we have (Navien) problem sod the kids in the house Sod the customer with a 14 month grand child we got your money and we don’t care wal thank you for nothing Navien and I can’t wait for the next trade show because I will be telling everybody who gos need your stand not to bother

No zero star available as that’s what I would have recommended …
We have a navien ncb500 that was fitted 2 months ago and started to lose pressure (3th December)and on inspection water was leaking from pump. Could not call navien customer care as it’s closed on Sunday,so called Monday morning. To tell them the problem with having NO HOT WATER and NO HEATING with two small kids 8 year old & 6 year old who is disabled. To be told by the very unhelpful customer care that an engineer would be with us on Wednesday 😖 I’ve have to source heaters to heat the house and kids rooms. I find this unsatisfactory and disgusting. Engineer came and did his best. A really lovely and helpful guy. Two days of trying to fix boiler an other part is required he has to get from navien to which they said it would be next week. Absolute shambles from navien.

I am extremely disappointed with this company’s handling of my Navien boiler, which has been out of service for over a week despite being under warranty. This has left my home without heating or hot water in the middle of winter.

As a single parent with two young children, the delay is not just inconvenient—it is unsafe. Despite multiple requests for urgent intervention, the company has failed to arrange a timely repair or provide adequate temporary support.

Under the Consumer Rights Act 2015, they are obliged to ensure repairs are carried out promptly and without significant inconvenience. This has clearly not happened.

I urge this company to take immediate action: arrange an urgent repair, provide alternative heating solutions, or offer a suitable replacement. Failure to do so will leave me with no choice but to escalate this matter formally.

This level of service is unacceptable and should serve as a warning to anyone considering their products or support.

Had a new Navien boiler fitted in November 2023 following a recommendation from the company fitting it. Supposed to be more efficient, readily available parts, reliable than the one I wanted. The engineer from the company that fitted it has been out to fix it 10 times in two years; there were also many occasions when they talked me through how to get it going again or deal with other issues. It has had two replacement pumps - the second took over three weeks to arrive. Last month a Navien engineer came to see it, and agreed it was not fit for purpose. There were eight parts put on order, with no idea when these would be available. I have had to make the decision to have the system taken out and replace it - I cannot keep waiting for Navien to do something. I have also gone to another fitter. I cannot risk more weeks without heating and hot water.

If I could give 1 star I would as what an absolute disaster we are having trying to get our Navien boiler fixed. We have waited in days and days and no-one turns up. No-one rings back and each engineer tells a different story ranging from one being sacked because of bad workmanship and then 2 weeks later they are back working but still do not turn up when told they will. Sadly we moved into this house with this boiler and have NEVER had so much hassle with a boiler in 6 months than we have had in 40 years with others. If you are reading this and live in Norfolk do not touch them as just no engineers when things go wrong (and they will!!!!)

DO NOT BUY! Worst boiler and terrible service. We have a Navien combi-boiler which was installed in 2017 by previous owners of the house. We had nothing but problems with it disconnecting and having to be re-set on a regular basis. It was next to impossible to find someone to service or even repair it and finally, after only 8 years (and 3 years out of warranty), there was a gas leak that we couldn't find anyone to fix - we have now replaced it with a much better boiler at considerable cost. The customer service was useless as they don't have engineers, and were able to recommend one plumber in our area who regularly serviced it to the end (he was also extermely busy so we ended up having to wait for his availability). Save yourself the trouble and don't bother with this inefficient company.

I called Navien UK regarding a combi boiler fault, after a few keypad entries I was immediately connected to an actual human who after taking note my details and the boiler fault, passed me onto support, who efficiently talked me through a boiler reset. The fault remained, and I was advised a technician would contact me. The next day a very helpful and well mannered plumber called me late in the evening, and after discussing the fault he said he could be with me in half an hour. True to his word, he arrived, fixed the fault and advised me of some helpful adjustments to the boiler to suit our heating and hot water demands. Thanks Reese, your a ⭐⭐⭐⭐⭐.

Design flaw. When the boiler gets cold overnight, the pressure natually drops a bit and the boiler errors 302 and automatically switches off ! Leaving me with no heating. I should not have to get up in the night to manually top up pressure. Problem reported but response yet.

Don't get a Navien, when they go wrong it is a hassle to get parts or engineers.
The house we bought had a Navien boiler. 1st cold snap it broke down. Called Navien as should be under warranty but they will not honour it as the last service was not done by old owners. All needed to get it working was to repressurise it, a procedure done often by owners and even told over phone by Navien we are allowed to do but the inlet hose had been left off by installer. Called the installer Boxt who said this is how they always leave the installation and this happens a lot so Navien usually can send a loop out which we can fix on to repressurise it. Called Navien who refused to supply as not under warranty even though we were happy to pay. Instead given a list of suppliers (only 3 in UK). Who upon contacting do not not have the part! We also tried to contact Navien engineers. Who we were told by Navien had to fit it for us. 1 never came back to us and 1 didn't have part anyway. Even if we manage to solve this puzzle box we have been informed unless the boiler was serviced last year (when we did not own the property) we cannot be under warranty. It's ridiculous because we previously had a baxi and previous owners didn't keep up service record as they were selling but once we paid for a service and had checked over we were put back in warranty so it seems Navien are being unreasonable.
Worse we are disabled and have been without heating during an amber warning for cold. No part to fix no engineer to fix it. No heat. At the moment surviving under electric blankets. We are probably going to have to rip it out and get a different boiler NOT FROM NAVIEN.

Kit excellent. Engineers excellent. Head office useless. Do not respond to calls, emails or requests for contact.

Yesterday and today Ian, operating in the Dumfries and Galloway area, did a fantastic job of getting the faulty boiler of our elderly and frail mother sorted out.
He was fast, effective and delivered what he promised. Stunning! We are most grateful!

(Ian is definitely worth 5 stars - but the Navian booking system was not good. It took us ages to get through, and then ages again to get us booked in).

I have been unfortunate enough to hand a Navien boiler installed. It has been two weeks and it has broken down twice already. Never having had to call a boiler service line for any such issue before, I'm now on the phone to them constantly. Please, please, take heed and do not buy one of these awful boilers. Get something that works instead - some tried and tested classic.

If I could choose half a star, that would still be too much. Customer service never call you back when they tell you the will. Engineers never call to say they’re on the way. Appointments are never kept by engineers or any contact with the customer service. Tell you that they will call you back they don’t. Tell you that the manager will call you they don’t. Tell you the Engineer will call you they don’t. After four days I have now got an engineer due to me. I have received a call saying he’ll be here today. I have lost three days at work waiting round because Customer services keep telling me I’m first call today waited round until 1 o’clock no-show. Then see on doorbell Engineer turns up at 2 o’clock without a call. One of the most inexperienced dealings I’ve ever had.

Buying this boiler has got to be one of the worst mistakes I’ve ever made. Within a short while of having it installed it broke down and ever since it’s one problem after the other. And tonight we have another problem.

I got this boiler installed in February 24 and I’ve had someone out up to 5 times with one problem or the other.

The last time it was an installer problem and the installer says nope it’s not them. So you’re pingponged back and forth until you’re sick of it all.

Tonight just like that the blooming thing packed up again. They don’t have a support system outside 5pm and 8am so if your boiler breaks (which our relatively new one habitually does) during those hours you really have had it. I’m assuming they don’t expect boilers to break when they are out of the office.

It takes days before they can get an engineer out.

Then there is the issue of the dynamics between the installer and the Navien folk with one always passing the blame on to the other.

It’s the worst service I’ve ever had with a boiler. I completely regret buying this product.

If I could give them minus 0 out of 10 stars I would’ve done!

we had the boiler installed a few years ago and it has been good.

we have had a few issues where the heating has stopped working but everytime we have called up an engineer has been booked to come and fix the issue

We had a navien boiler installed last year and honestly it was such a mistake. I did check Trust Pilot before we bought it and was reassured by the positive reviews. However, ours broke within six months, and - since then - it has never been right. We've been messed around quite a lot with Navien saying it is an installation fault, and the installers (BeSure) saying that is is a manufacturing fault. The two companies don't seem capable of speaking to each other, so I have had to spend a lot of time on hold to both, which is extremely annoying as I have a full-time job and a toddler. Recently, it broke again and we paid (paid!!) for an engineer to come out, who informed us that we need an entire new boiler as the one we currently have is unsafe. Once again we are being bounced between BeSure and Navien, and are now living with no heating or hot water. I don't know if we've just been unlucky but I really would NOT recommend that you get one of these boilers.