Worcester Bosch 4000 Boiler Review: Plumbing's Verdict

In this review of the Worcester Bosch 4000, we review the latest Worcester Bosch 4000 combi boiler with Allen Hart. The Worcester Bosch 4000 is one of Worcester Bosch's most advanced combi boilers that features an easy-to-use digital display, high efficiency, and a more compact design.

[Dibbles-]

We had a Worcester Bosch 8000 boiler fitted in November. We thought Heatable were supposed to be approved installers. Which meant that a system flush would be done as mentioned in the details of the quote online & on WB website.
But the whole thing turned into a nightmare. NO SYSTEM FLUSH! NO LIMESCALE REDUCER! NO SHOCK ARRESTOR! piles of redundant plumbing items hidden under our loft insulation, and the walls were over filled with concrete half an inch higher than the plaster in my kitchen. Wires were left hanging from walls, and the dirty water from redundant old water tanks dumped all over my driveway. He even removed the drain vent and never replaced it, so no future engineer could drain the system. So far we’ve had to have a brickie out to repair the wall and my driveway will need to be resealed after being jetted washed when the weather improves. As for Heatable, I had your Director shouting down the phone at me last night stating YOU NEVER DO A SYSTEM FLUSH on a Worcester Bosch installation, angry that Joel (after care) had arranged it. Joel also arranged a limescale reducer, which we were told was gesture of goodwill! LOL WB require it when your water hardness is 270ppm. We weren’t even asked if we had hard water. Two months of emails and cancelled appointments before and after fitting. Now your Director is angry that Joel corrected all these disaster, although no one as yet has even looked into the shock arrestor.
I can’t even get online at WB as the warranty has been done wrong. You also sent me a ten year warranty certificate, after 2 months of asking. Not the twelve years stated. Now I have your Director shouting down the phone, apoplectic that a system flush was done. I don’t even know if my warranty is valid after all this.

[orpheusjones]

Just had ours installed. Why is it so loud? Not only the general sound of the boiler, but also the noise of water flowing through the pipes? One of the selling points of this boiler is that its meant to be quite. How is it that boilers 15 years ago made less noise? The old baxi we had would switch off immediately after turning off the tap. This takes about a minute. Having just spend thousands of pounds, i'm not sure what to do.

[michaelstaley]

Very good informative video I own an 42cdi classic very pleased with mine so far .

[paul-jfb]

Any improvement on the flow valves that continually pinhole

[Daz-L-CV]

@9:06 you say the 4000 will fit on the "I junior jig" the 4000 will not, as the I junior has 2 small hooks at the top the 4000 has one central hook, its the screw fixing footprint that is the same. (but you get the jig with the boiler). 14:55 the gauge in the boiler is NOT for the customer, as will break the combustion seal. (could not see the easy control as an option on your website?). you can install the PRV pipe via the new jig before hanging the boiler - I have never had any issues. good video tho very informative :)

[Evolutions-em]

Learnt so much from this ordering one from you today!!

[gasservenw]

Certainly no plastic in the packaging. It's all used inside the boiler

[Rustydog]

Thanks guys you are very knowledgeable bunch and that’s appreciated. Recently attended this training. About to purchase a Bosch unit for my house and came upon your video.
Aurora colorado viewer here. Greeting’s amigos.

[marklloyd]

Fantastic guys. This video was so informative that I have just purchased one and looking forward to my insterlation |Tuesday 23/07/24 ..

[weechid]

How do you switch the bloody thing off? My Comfort plus II rf thermostat has failed and I can't get the heating off.

[kpr]

Had mine installed in April so not really used heating until now.
System seems to be cycling constantly. Its fitted in a cupboard in our bedroom on a common wall with our neighbour so I’m keen that it cycles as little as possible, especially overnight
How would I set it. House is well insulated so only have to put heating on for an hour in the morning. Many thanks

[grahamleathwood]

In my opinion, Worcester boilers sell on a reputation of reliability and good build quality. A reputation that has been earned over the years. However nowadays, i'm not that sure that the reliability / quality is still present. Given the upwards price adjustment of the Worcester compared to e.g. the IDEAL equivalent. I think it's a good idea to at least do your research before committing blindly on the basis of the reputation they used to have.

[rodgerq]

Good video lads. Impressive how low the thing modulates to. Would have liked to have heard some info on the weather comp control side of things. Good video nonetheless, i would consider this as a replacement when my greenstar classic kicks the bucket.

[RobFisherUK]

7:30 I'm still not convinced about range rating: why would I care about setting the max output if it's automatically going to modulate down anyway as soon as it detects the flow temperature rocketing up?

For that matter, I'm not sure why cycling is bad. 6kW at a 50% duty cycle is surely identical to 3kW.

[johnw]

I have a 2014 WB Si Compact 30 kw, is there a low Nox plug available for this? If I eventually changed to this 4000 model is my current jig the same? Can the 4000 be used with an outside sensor for weather compensation? Will it work ok with Nest Gen 3? Surely range rating is via a menu system and you don't need to be Gas Safe registered to alter that? What pump is in this please?

[bikeanddogtripsvirtualcycling]

im getting one of these installed in a few days. old boiler was a good 25 years old and has provided no heating for going on 4 years

[Dibbles-]

Hi, Worcester Bosch website says their approved installers, must do a system flush, and Allen I note you say this is a must in your installation video. Does heatable, as an approved installer do a system flush when they install a Worcester Bosch boiler, as required by Worcester Bosch?

[syedsameer]

hi..what do i do if the mains pressure is not that great and dont have the space for a cylinder for a system boiler?

[neo_]

Great video, I was totally sold on a Veissman 100 as the modulation ratio is impressive and Wochester don’t market their ratio anywhere, so I had no idea it could modulate down to 3KW. I currently have a Baxi Platinum which has a manual adjustment down to 10KW which is way too much for my house.

[devbhari]

Question for heatable, Allan or any experts. I had this boiler installed last April from British Gas and nothing but problems. The PCB board had to be changed after six months but the major issue that can’t be fixed is the flue leaks from the outside. British Gas state this is normal for a condensing boiler but my old boiler was condensing but never leaked. Worcester state it shouldn’t leak and not been very impressed with their follow up as they sent an engineer that stated there’s a fault but there’s not but he can’t find the fault. Should the flue leak?