Confusing boiler situation

Author
Discussion

skinnyman

Original Poster:

1,637 posts

93 months

Friday 21st October 2016
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Firstly, it's a Baxi 105e combi, and the first combi I've had, so still getting used to how it works.

So, I noticed this morning the pressure was low, so I topped it up to 2 bar, just got in and it's dropped to 1.25 bar. So I fired it up to see if it dropped further when on, but it's increased up to around 1.6 bar, and seems to be holding there. No obvious leaks anywhere, and the waste pipe is dripping slightly when it's on, a drip every 2-3secs I'd say.

Is this normal behaviour? Or should it be holding its pressure better?

Happy Jim

968 posts

239 months

Friday 21st October 2016
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That'/ completely normal......for a boiler with a problem;-). If it's perm dripping then it's perm losing pressure..If you're lucky it's a bit of crud under the over pressure valve, if not then probably the pressure vessel has given up.

Jim

Busterbulldog

670 posts

131 months

Friday 21st October 2016
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You shouldn't be able to see the wastepipe dripping..are you sure it's not the safety discharge pipe. Is it a copper pipe ?

dirkgently

2,160 posts

231 months

Friday 21st October 2016
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The expansion vessel will need recharging, it is supposedly checked on a service but no one ever dose.

skinnyman

Original Poster:

1,637 posts

93 months

Friday 21st October 2016
quotequote all
Busterbulldog said:
You shouldn't be able to see the wastepipe dripping..are you sure it's not the safety discharge pipe. Is it a copper pipe ?
Yes sorry, the bent over copper pipe outside, that's dripping, with a sizeable wet patch under it too tbh.

It was "serviced" last month by BG, but this being a free service I think the bloke basically turned up to check a boiler was there

SteveScooby

797 posts

177 months

Friday 21st October 2016
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I had the same issue with my Baxi, called Baxi out under warranty and they re-inflated the expansion vessel. A few weeks later had same problem so they came out again and this time replaced the expansion vessel, it's worked fine since (fingers crossed)

skinnyman

Original Poster:

1,637 posts

93 months

Friday 21st October 2016
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Balls, might have to go down that route then, I think they found a fixed fee repair service too

Wombat3

12,138 posts

206 months

Saturday 22nd October 2016
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2 bar seems high - I was told to keep it around 1 bar (when cold) it climbs when its running but not to 2 bar

ChrisNic

592 posts

146 months

Saturday 22nd October 2016
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Turn the heating on and check all the rads come up to temperature normally.

We had a towel rail fitted and months later when putting the heating on we were loosing pressure in the same way. We had Worcester out, the installer out and ultimately a leak detector company out then I discovered a stuck valve on said towel rail which lead to a huge air lock.

I don't know the reasons behind it but once the rad was sorted and air shifted we had no further problems.

skinnyman

Original Poster:

1,637 posts

93 months

Tuesday 25th October 2016
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Bled all the rads, was loads of air in the towel rail. I've noticed now when the heating is on the pressure needle is steady, whereas before it was wobbling all over the shop.

Just a thought though, about 5 weeks back I pierced a heating pipe with a screw (I screwed every single floorboard to every joist in a 4 bed house, circa 1000 screws, I pierced the pipe with 2 screws left.....), anyway, turned the water off, emergency plumber came out, drained the system, and replaced a small section of pipe, job done. Upon turning the system back on it had a lower pressure error, topped the water up and it went away. Was this sequence of events likely to have caused this issue? Should anything else have been done after draining the system, such as, repressurising the pressure vessel?

skinnyman

Original Poster:

1,637 posts

93 months

Wednesday 2nd November 2016
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Well after the rad bleed things are a little better.

The pressure is low, it sits around 0.75 bar and increases to 1 bar when on, I've got the temp set to about 1/3rd and things like hot water pre-heat off, so don't expect it to reach big pressure numbers when on anyway, so even though its low at least its stable. However, there is still a constant damp patch below the copper pipe outside, so it seems to still be leaking, yet holding its pressure, so not sure whats going on now.

northwest monkey

6,370 posts

189 months

Wednesday 2nd November 2016
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It sounds to me like the pressure vessel needs "pumping up" or the pressure relief valve needs replacing. I'm not a boiler engineer, but ours was doing exactly as you describe and that's what we had done.

Belle427

8,947 posts

233 months

Thursday 3rd November 2016
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The pressure relief valve had a habit of not sealing and leaking on mine, this was quite a cheap fix but I had various other issues with it including the expansion vessel.
It lasted 10 years before I decided to change it, my plumber took an alarming amount of these boilers out and stopped installing them.
I seem to remember turning the pre heat feature off extended its life a little.
Not wishing to put a downer on things but just my experience on the 105e, I suppose 10 years is a good life for boilers these days.