Bain of my life Baxi 105e

[RobFurn]

I have a Baxi 105e and has yet another problem
The boiler is in my garage, yesterday evening a pool of water was present below the boiler and the pressure had dropped to below 0.5bar. The water is brown so it must be from the CH. I represured it and left it. This morning another pool of water is there and agin the pressure is below 0.5bar. There are no leaking pipes, so I assume a valve is venting water. After a quick internet search a faulty expansion vessel is hot favorite. Can you experts confirm this? if it is this can you confim how much of a bastard it is to replace, cos I bet its right at the back in a totally inaccessible place

 

[howmuchlonger08]

Just fit a external exp vessell on the wall and connect with 8mm tube, easy job and cheaper than a Baxi part

 

[RobFurn]

Thanks, you say easy job and I'm sure it is, but i wouldn't know where to start, and chance you could list what is required?

 

[howmuchlonger08]

8 litre exp vessell with wall backet, 2mtrs(?) 8mm tube which will connect on to the exp. vsl. connection..... couple 8mm comp. elbows and away you go (22mm no 2 with reducer down to 8mm)

 

[RobFurn]

Hmmm, not sure if i understood all of that, can you paint me a picture
as far as I can tell cant I just tee a new EV into the return pipe?

think I will test the suspect faulty one first by pressing in the valve centre pin, if I get water then its knackered, if air then it jut needs topping up right?

 

[darren17]

is the water coming from the prv
is there enough air in the ev should be about .8
the ev should be pressurised to about 1.5 bar

 

[RobFurn]

I cant actually see where the water is coming from as everything is dry except for the PCB plastic housing, I will have to sit and watch it

Going to check the EV when I get home, I'm hoping it just needs pumping up but knowing my luck the bottomless pit that is my boiler will require a new one.

 

[darren17]

to check the ev there is a valve like a car tyre simply take off the dust cap and press down on the needle to see if air or water comes out
if no water comes out then the ev is fine it just needs to be pumped up to about .8
if the prv is leaking simply replace it they are only afew quid
a prv once it has let water out gennerally gives trouble
if there is no air in the ev that would cause the prv to open as the pressure would rise

 

[namsag]

The best thing to do would be to take the front of boiler off and actually look for where the water is dripping from before you start changing things.
If you have a pool of water under it then its dripping from somewhere

 

[RobFurn]

OK thanks that's very useful, when topping up the EV do I have to drain the system of water, I read somewhere that I have to do this?

 

[darren17]

yes about a bucket or two
but that depends on the amount of water already lost from your system
you could simply drain the system if you wanted to but that's not really needed

 

[powell30]

Brown water?? Perhaps a lot of your problems stem from poor maintenance. Sort this out.

Check if the prv pipe is where the water is venting from first. As Namsag states it's pointless just going off and doing things unless it is going to work!

I know sometimes prv's are vented down on garage floors rather than direct to outside.

Don't bother with 8mm-22mm etc etc. If you need to fit an external vessel a 22mm to 15mm flexible will connect direct from the cap on the return pipe to the expanssion vessel

 

[RobFurn]

Brownish water its not hot chocolate or anything its just a bit off , thought this may be because some additive has used "Sentinel" sticker on the boiler.

I have a feeling its when the boiler switches on after being off for a while, its funny though as even when the water is vented from wherever, the boiler still continued to function even below 0.5 bar (not good i know)

As I said there's no water present on any of the pipes, I will do some testing tonight and report back

Thanks for the advice

 

[RobFurn]

Right then, the Water is venting from the 3 bar PRV.
I have tested the EV by pressing the tip in the valve, only air comes out no water. The pressure is at about 0.5 bar. What procedure should i use totop it up, just use a car pump? do I need to drain the entire system of water first? please help

 

[darren17]

you need to drain at least a bucket or two
then the prv might re-seat itself,but there could be just a bit of dirt from stopping this
if thats the case just replace it
the pressure inside the ev should be about .8
the actual system pressure should be about 1.5 bar when it is cold and disconnect the filling loop when this is done.
use a simple tyre guage to check the pressure in side the ev
don't use the pressure guage on the unit , that is only for telling you the system pressure
also when you only got air out of the ev that shows the diaphragm is not burst
good practise would be to add a pipe to the prv to drain outside
once you have done this it would be a good idea to clean the system and add an inhibitor