Never-ending problems with WB Greenstar 4000 15Kw system boiler

Iso

FreeBear said:

JohnB47 said: It might help to know that the condensate water on the Greenstar range (and some others) is first stored in a little internal tank and when this tank has filled to a certain level, siphonic action drains it down the condensate pipe. There is no pump as such I believe. It takes a while for the condensate to build up to the point of siphon, so that might explain the three week delay to the problem showing.

I know you shouldn't have to do this (the engineer should have) but if it was me, I would look under the boiler and find the white plastic pipe running vertically down at the back. I would look at the top and find how it was fitted to the boiler - probably some sort of compression joint - and undo it. I would then move the pipe to the side and put a container under the fitting to catch any drips or flow and turn the boiler on. If it fires up as normal, then the condensate pipe is indeed the problem. If it doesn't, it can't be the pipe, so I'd report that to WB.

The condensate trap should be primed at installation time by pouring ~200ml of water down the exhaust flue connection (before attaching the flue).

The white plastic pipe is usually a push fit over (or in to) a rubber spigot, so easy to disconnect. With my boiler (a Viessmann), it is a flexible length of pipe about 300mm long.

Not sure if it was primed - I will ask. It sounds like it is too late to do it now.

The installer never seems to touch the part of the condensate pipe that connects with the boiler, just the lower parts. We don't want to do anything that may leave us being blamed for causing damage - particularly as the WB director is  already arguing with the WB engineer and siding with our installer (according to our installer)!

I am beginning to think the whole thing needs taking out and re-installing...

I was hoping to add a video of the boiler making the gurgling and showing the condenser tank but cannot work out how to do this / if it is possible.

Iso

Albermarle said:

The white plastic pipe is usually a push fit over (or in to) a rubber spigot, so easy to disconnect. With my boiler (a Viessmann), it is a flexible length of pipe about 300mm long.

I have a WB greenstar ( not the same model as the OP)

A short length of rigid plastic tube comes out from the bottom of the boiler at an angle. As you say this is connected to the white plastic outlet pipe by a rubber spigot. It is easy just to pull the white outlet pipe out of this spigot as I have done it before.

You are making it sound as if it is something we can do... is it this bit I have circled? Or do we just pull the pipe down from where it fits into the boiler?

JohnB47

When my wb 'green star 8000 Life' was installed, they left an installation guide, which has diagrams and instructions concerning the condensate siphon and pipes. Have you got that document? I'll send you pictures of mine if you don't. It might help.

In my case, the white plastic pipe comes up vertically, then into a right hand bend at a right angle to the wall, then through a hole in a metal plate. A rubber hose, the outlet from the siphon, is simply pushed over that white pipe. 

It should, I think, be easy to pull that rubber hose off the end of the pipe and try running the boiler with the condensate pipe ' out of the circuit'.

Edit: your picture seems like my boiler. Don't touch the white pipe. Look up from underneath. Can you see a rubber hose pushed over the end of that pipe? That's what you could pull off, I think. Also, just seen that picture you posted of the siphon - it was blank earlier. I'm not sure now if the siphon is connected to the while pipe like I said but it should come off easily. What happens when you try running the boiler while looking at that assembly. Can you see if the noise is coming from that? 

FreeBear

JohnB47 said:

When my wb 'green star 8000 Life' was installed, they left an installation guide, which has diagrams and instructions concerning the condensate siphon and pipes. Have you got that document? I'll send you pictures of mine if you don't. It might help.

Easy enough to find online. WB have it available on their web site - https://www.worcester-bosch.co.uk/professional/support/literature/greenstar-4000-system-installation-manual (it's where I cribbed the fault finding from).

Iso

JohnB47 said:

When my wb 'green star 8000 Life' was installed, they left an installation guide, which has diagrams and instructions concerning the condensate siphon and pipes. Have you got that document? I'll send you pictures of mine if you don't. It might help.

In my case, the white plastic pipe comes up vertically, then into a right hand bend at a right angle to the wall, then through a hole in a metal plate. A rubber hose, the outlet from the siphon, is simply pushed over that white pipe. 

It should, I think, be easy to pull that rubber hose off the end of the pipe and try running the boiler with the condensate pipe ' out of the circuit'.

Edit: your picture seems like my boiler. Don't touch the white pipe. Look up from underneath. Can you see a rubber hose pushed over the end of that pipe? That's what you could pull off, I think. Also, just seen that picture you posted of the siphon - it was blank earlier. I'm not sure now if the siphon is connected to the while pipe like I said but it should come off easily. What happens when you try running the boiler while looking at that assembly. Can you see if the noise is coming from that? 

Yes, we have the installation guide and user manual. Thank you, now I understand. I thought you meant the top of the condensate pipe. I had not realised there was a flexible hose between the tank and the pipe. We know the white pipe is the condensate pipe (having discussed it with the installer!) and know where the condensate tank is and how to get to it so should be able to locate the flexible hose that joins them together We will have a good look at the installation guide / condensate tank / syphon / pipe so we can disconnect the hose between the tank and the pipe before attempting to fire up the boiler when it malfunctions. Of course the cylinder sits in front of the boiler which makes everything harder to reach / look at   

JohnB47

Good plan but I wouldn't be removing any parts just to get at the flexible pipe (apart from covers of course). If it looked really awkward, I'd just mention the idea to your installer and let him do it - he's not likely to void the warranty.

Just out of interest, how is the boiler performing at the moment? Sounds like it's working to some extent.

Lorian

It might be useful to know assuming it's not been turned off in the config when the boiler is turned off and back on at the mains the 4000 should fire at a low rate showing a sort of + symbol flashing for 15 minutes while it pre-fills the syphon.

Iso

JohnB47 said:

Good plan but I wouldn't be removing any parts just to get at the flexible pipe (apart from covers of course). If it looked really awkward, I'd just mention the idea to your installer and let him do it - he's not likely to void the warranty.

Just out of interest, how is the boiler performing at the moment? Sounds like it's working to some extent.

It is working at the moment and has not malfunctioned since Thursday when they replaced the 4x 90 degree angles with 2x 45 degree angles. Fingers crossed!

Iso

We have noticed a short - probably about 1 second - gurgle coming from the boiler shortly after it starts in the morning.  Is that normal? 

JohnB47

No gurgling from my Green star 8000 at any time.