Baxi 105e Expansion Vessel failed?

[Brockk]

I have been trying to repressurise to no avail - can someone please confirm whether it sounds like it is gone?

Here's what I am doing:

- Close CH flow and return under boiler
- Open tap and let water drain
- When it stops, attach pump to vessel and switch on - water then continues to drain
- I continue to switch pump on/off until water completely drains (I also hear gurgling type sounds towards the end)
- With all taps in the same position I turn on pump but the pressure does not go up, instead I can hear air escaping via the airlock and the drain tap

Sounds like it has gone right?

The only way I can get pressure in there is if I add some water back in via the filling loop, turn the tap off, and then turn on the pump, but even if I manage to get hot water working it will need to be redone after a few hours or the next day. Pretty sure the vessel has gone but just want to check with you all just in case I am missing something.

 

[gas112]

you mean little white drain tap in boiler right handside
When you attach your hand/foot pump to vessel after removing dust cap you pump it up to one bar on your pumps gauge which will force any water in vessel out of little white drain valve . if pressure drops take it back to one
Then close little drain valve open flow and return then open filling loop and take boiler gauge to 1.5

 

[Brockk]

you mean little white drain tap in boiler right handside

Yep, the white drain tap just behind the red PRV.

When you attach your hand/foot pump to vessel after removing dust cap you pump it up to one bar on your pumps gauge which will force any water in vessel out of little white drain valve . if pressure drops take it back to one

It forces out the water... but is impossible to get it to 1bar - the air just keeps escaping via the airlock (above the pump) or through the white drain tap.

Then close little drain valve open flow and return then open filling loop and take boiler gauge to 1.5

I can't get to this stage because of the step above - I use a powered pump and the air just seems to 'leak' out. Would this mean the expansion vessel has gone?

 

[gas112]

Sounds like the diaphragm in vessel has split if you have a vertical flue or it exits either side then the vessel can be removed and changed with boiler on the wall if you have room above boiler and ceiling . If flue goes straight out the back or you dont have the room then its far bigger job .
a remote vessel can be fitted outside of boiler on return pipe and the existing vessel capped off as if the diaphragm is split it would prob leak out the dust cap when pressurised up

 

[Brockk]

Thanks gas112, I thought it was the vessel as well (it's been on the way out for a couple of years).

I think I read someone managed to get a new vessel in via the side, but I have a plumber coming around next week so will get him to do it anyway (even though I've watched the Baxi vid and it seems straight forward enough - the flue screws can be loosed and the flue pushed out to allow room for the vessel to be lifted out).

 

[gas112]

Cracking boiler keep as long as you can mine is 22 year old

 

[Deleted member 267285]

Cracking boiler keep as long as you can mine is 22 year old

We had some on our books, didn’t get chance to work on them much, gutted having read stuff on here. Replaced with modern intergas crap with parts that fail for fun.

 

[Brockk]

Any thoughts on getting a refurbished vessel? They are £50 or £85 new (I'm leaning towards new)

Cracking boiler keep as long as you can mine is 22 year old

Mine's about 20 years old and the only thing I remember going wrong with it is the filling loop, diaphragm, and water thermometer/sensor has needed changing - as well the expansion vessel issues. Other than that it's been great!

Are the new Baxi boilers more efficient/cost effective? Are they worth upgrading too?

 

[Deleted member 267285]

For £35 extra, get new. Not sure how you can refurb a vessel.

 

[gas112]

refurb basically means they have taken it off an old boiler and cleaned the outside of it pumped it up and possibly checked its held its pressure

 

[Brockk]

Thanks both. Does this one look like the correct one?

Baxi 248722 Expansion Vessel with Storage for Combi Instant & Potterton Performa | eBay

Baxi COMBI INSTANT 105. Baxi COMBI INSTANT e 80.

www.ebay.co.uk

It has the double connectors on the bottom which mine has, but doesn't appear to have the polystyrene casing which mine does. Mine is like the one in this video:

My GC number is: 47 075 09

Guess it's ok?

 

[gas112]

Yeah its right one for an instant .
Lets just say i would think they had already done a wee bit of work on that to loosen it off as with the polystyrene on the instant they usually do not come out anywhere near as easy as it does in that video

 

[Brockk]

A plumber was able to come out today and said from how I've explained it he agrees the expansion vessel has gone, but he also thinks it's leaking from a few different places (one of which is the diverter valve as the motor was all wet). He thinks it'd probably not be worth me paying him to do it as he thinks it will take a few visits and a number of different things needing replacing, so the cost will rack up.

He thinks my best bet is to replace the expansion vessel and diverter valve myself (tho be prepared for other things that might need fixing) or to get a new boiler installed.

I had actually already ordered a diverter valve and motor as I thought they may have been the issue anyway, so was wondering whether any of you had any thoughts? Should I fit the diverter valve and motor first, or order the expansion vessel and fit that first?

One thing I did notice was a drip/leak from the pipe that runs along the left hand side of the boiler (see red arrow in diagram below) - I'm guessing the O ring or seal has gone (and I am guessing because I must have over-pressurised the vessel because when these issues started there was a leak from the front of the chamber and I am guessing it was this pipe) Here's where that pipe is (red arrow):

Any thoughts? Should I go ahead and replace the vessel, diverter valve and motor? (I've watched the YouTube vids so think I am can do so competently) or do you think I should just get a new boiler?

 

[Deleted member 267285]

Looks like a compression fitting, so maybe attempt to tighten first? Could be a fibre washer, but @gas112 will know better than me. I would maybe try and dry the motor, depending how bad it’s been leaking, and replace the diverter cartridge.

 

[Brockk]

Thanks @CBW - I went to fit the diverter valve but discovered the one I bought (the one they advertised for the 105e) is too big!

Here's the one they sent (left) vs the one that's in my boiler (right):

That's before I cleaned it mind - it was black and basically closed shut. So I cleaned it, greased it, then put it back in and now.... I have heating!!!!!

I have a couple of questions:

1) Does it look ok now that I cleaned it or should I purchase a new one? (The only one I can find that looks anything like it is this repair kit off Amazon: https://www.amazon.co.uk/HTS-Compatible-Duo-tec-Instant-Diverter/dp/B09GMCP75K - does that look ok or is there a better replacement around?) I will check the diverter valve tomorrow for any leaks (there was water pooling at the top when I went to remove it).

2) Do you think that my expansion vessel might be ok after all? For instance is there a possibility that if the diverter valve was stuck in an awkward position it might have been that that had been preventing the expansion vessel from getting a charge? (I didn't fully empty/recharge the vessel as I didn't want to jinx anything, not that I finally got heating back on!)