Worcester Bosch Greenstar 30Si pressure issues

Hi

Im after some advice please.

Had this boiler fitted around 2006-2007 and since then we have had a service plan with Worcester who do a service once a year and if it goes faulty they will come out and fix it.

Back in January I noticed that the pressure had dropped to 0 so I toped it up to around 1.5 bar and thought that was that.

Within a few hours maybe even less it was back at 0 again which clearly isnt right so I called them out and they changed the PVR, Expansion Vessle and I believe a fan I think he said it was as they were faulty/leaking

That has stopped the pressure droppping within a few hours to 0.

Unfortunalty over the period of around 7-10 days the pressure slowley drops and then ends up at 0 again.

Now I didnt really play with it to much as I dont want to mess with it to much as im no expert and when it comes to things like boilers and gas for me thats one for the professionals.

So when I saw it was at 0 I topped it up straight away but again after 7-10 days it drops.

So I called Worcester out again who came and did a few checks and said the PVR is fine and checked the pressure gague and said that was also fine.

He also said it cant be the heat exchanger as the design of this model and I quote is impossible to leak.

What I didnt realise until now was he didnt even try any taps in the house he literally just looked at the boiler.

His conclusion was that there must be a leak in the central heating system and that we should put some leak sealer in and see if that helps.

So with the help of a friend we isolated the towel rail drained out some water and added a bottle of Fernox F4 then turned it all back on and repressured the system to around 1.5 bar.

Later in that day it dropped to around 1.2 bar and thats pretty much stayed steady at that for over a week.

The last couple of days it was reading around 1 bar and again when I checked it this morning.

But all of a sudden it dropped straight down to 0.

Rather then top it straight back up I noticed that the heating for example wasnt on so I waited for that to kick back in and see if it changes and indeed it climbed back up to around 0.8.

I still havent topped the system back up yet but the other thing I have noticed is that say I run the hot tap in the kitchen after I finish the boiler sounds a bit like a toliet thats just been flushed and is refilling.

Currently its back on 0

Like I say im no expert but for me if there was a leak somewhere where it was slowly droppiing surley it wouldnt just drop from 1 to 0 after a steady week or so around 1 and then also climb back up again even if it wasnt as high as before.

Bearing that in mind surely this would be a boiler issue?

Sorry for the long post but can anyone offer some advice please.

Im quite happy to call a plumber round to investigate a leak but a lot of our pipes are underground in concrete and hard to imagine it the upstairs floors are also concrete so finding a leak if its that would be a nightmare in itself.

But I dont want to call one out if its still possibly the boiler and waste my money for no reason if that makes sense.

Thanks in advance.

Nex said:

What I didnt realise until now was he didnt even try any taps in the house he literally just looked at the boiler.

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Why would he try any Taps ? the water that comes out of the taps has nothing to do with any pressure loss.

Nex said:

His conclusion was that there must be a leak in the central heating system and that we should put some leak sealer in and see if that helps.

So with the help of a friend we isolated the towel rail drained out some water and added a bottle of Fernox F4 then turned it all back on and repressured the system to around 1.5 bar.

Click to expand...

Well that is not correct, if you look at the installation manual for your boiler page 34 it states:

The addition of sealing agents to the system water is not recommended as this can cause problems with deposits left in the heat exchanger.

You may have caused problems with your warranty, a WB engineer should not be recommending you do this

Thanks for the reply.

Well like I say im not expert but when I run the hot water from the tap it does seem to change the pressure slightly.

I didnt know about the sealing agent in the manual and thank you for pointing that out.

But like you say I have added it now so its to late and of course he told me via word of mouth rather then say written down or on an email so if a problem does occur for this and im not saying he would be he could easily say I never said that. :/

Nex said:

Well like I say im not expert but when I run the hot water from the tap it does seem to change the pressure slightly.

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That is because when you open a tap the boiler senses it and the boiler pump comes on which will have a slight effect on the guage pressure, the water from the tap and the water from the rads should never meet

I know they have changed what you keep calling a PVR it is actually a PRV (pressure releif valve) Tie a small bag or balloon over the outlet and see if it collects any water

ianmcd said:

That is because when you open a tap the boiler senses it and the boiler pump comes on which will have a slight effect on the guage pressure, the water from the tap and the water from the rads should never meet

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Thank you for explaining that.

ianmcd said:

I know they have changed what you keep calling a PVR it is actually a PRV (pressure releif valve) Tie a small bag or balloon over the outlet and see if it collects any water

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Apologies yes PRV.

Thats going to be slightly tricky looking at it as when it was fitted they actually plumbed a pipe down the ouside of the wall and into the ground and since then we have had the drive done.

I need to have a better look tomorrow in the daylight to see if its accessable without ripping out loads of stuff.

The pipe from the PRV should be open to atmosphere, not buried.
Cut it off a couple of inches above ground and see if it's dripping.

Nex said:

Thats going to be slightly tricky looking at it as when it was fitted they actually plumbed a pipe down the ouside of the wall and into the ground and since then we have had the drive done.

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No that will be the condensate pipe, the PRV goes through the wall and then points back towards the wall and has to be visible or a tundish has to be fitted

kidgreen61 said:

The pipe from the PRV should be open to atmosphere, not buried.
Cut it off a couple of inches above ground and see if it's dripping.

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ianmcd said:

No that will be the condensate pipe, the PRV goes through the wall and then points back towards the wall and has to be visible or a tundish has to be fitted

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I have seen the style you mean my ex had that on her house but I dont have it like that.

To make it easier I just nipeed outside and took a couple of photos.

Apologies they are not the best but hopefully you can see enough.

post a pic of the boiler and the pipes below it

ianmcd said:

post a pic of the boiler and the pipes below it

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Thanks for the replies.

Hopefully this is ok for you.

The pressure releiv valve pipe work has not been installed properly, regs say that any discharge has to be visable, possibly was before you had the groundworks outside done, that is not causing the pressure loss but prevents you checking if it is that , also that condensate pipe should be lagged, and should also have an air break installed surprised the WB engineers missed that

ianmcd said:

The pressure releiv valve pipe work has not been installed properly, regs say that any discharge has to be visable, possibly was before you had the groundworks outside done, that is not causing the pressure loss but prevents you checking if it is that , also that condensate pipe should be lagged

Click to expand...

Ok thank you.

Apart from that is there anything else I can check or is it time to call a plumber in?

Check your house insurance to see if you have trac and trace on it

Im with esure which has something called Trace and access

What is covered?If the Buildings are damaged due to water escaping from water tanks, pipes, equipment or fixed heating systems in the Home, We will pay for the reasonable cost of removing and replacing any part of the Buildings necessary to find and repair the source of the leak and making good the removed or replaced elements of the Building.

Thats apparenetly covered upto £5000

I take it thats the same sort of thing as you were suggesting?