Vokera Linea Max losing pressure

[tmc888]

Have had a gradually worsening problem with Vokera Linea Max. We have to repressurize very regularly now to between 1-1.5bar.

I have located red pressure vessel but as suggested by other sites I cannot locate any PV on the vessel that may be leaking. The whole press vessel feels warm to touch but a diagram I have seen seem to suggest that it has an internal diaphram which would create a air pocket at top of press vessel. We recently had the boiler serviced and this vessel was press checked and was ok and engineer suggested the loss of pressure which was not as regular at the time was due to a CH system leak.

Can someone give me more advice on the possible causes of the loss of pressure, anywhere I can check for the problem and the common way to fix this issue

thanks

 

[nickso]

burst expansion vessel, PRV leaking, primary heat exchanger leaking, isolation valves leaking, DHW heat exchanger leaking at pipe connections are all favourites on this awful machine.

the system could also be leaking anywhere.

 

[tmc888]

Nickso

thanks for the feedback. Seems to be quite a few options. How do I separate each and identify the actual fault. If there are leaks around the boiler wouldn,t this be seen visually for some of the components you speak off. I have been all over the pipework and valves and not a leak in sight.

Starting with the expansion vessel : if the whole vessel is warm from top to bottom does this indicate a damaged internal diaphragm etc. Need a little checklist to pinpoint the actual fault with all these options.

hope you can assist

 

[scatmanjohn]

If the problem is with the expansion vessel you will have water coming out nf the pressure relief pipe (usually 15mm copper pipe going outside)

If thats dry my money is on the main heat exchanger.

Very common on this model.

 

[nickso]

as scatman says.

you can safely remove the outer cover (two plastic screws on front, then lift out and up). from there you can see pretty much everything that leaks apart from the heatex.

 

[Adrian13]

Have a similar problem with my Vokera Linea - losing pressure gradually. Call out guy suggested a leak on the system, but didn't check anything else (scratchy chin & sharp intake scenario!!) so interested re the other options as mentioned above. Currently planning to insert Fernox F4 leak sealant to system to attempt to rectify.

 

[scatmanjohn]

Have a similar problem with my Vokera Linea - losing pressure gradually. Call out guy suggested a leak on the system, but didn't check anything else (scratchy chin & sharp intake scenario!!) so interested re the other options as mentioned above. Currently planning to insert Fernox F4 leak sealant to system to attempt to rectify.

Get someone to check the main heat exchanger.

 

[Adrian13]

thanks John - are there any obvious signs if it is the Heat Exchanger being the issue? Please note I have noticed very infrequent water drips from boiler, but not in my opinion enough to impact the pressure gauge swings so much, but am not a pro at these, but keenly interested.

Suspect as above could be a number of parts affected.

 

[tmc888]

Thanks for all the replies

I can see no leaks anywhere visible inside at all. If the main heat exchanger is suspect then how do I test that or how will an engineer test. I have seen quite a lot of other threads were the engineers called out don,t seem to know there ass from there elbow and I don,t want my boiler ripped apart until i know as mush as poss. If it is the heat exchanger then what would be the problem with this?

Can you let me know how you get on the fernox Adrian13 and I would be interested to know exactly were you are inserting this into your system.

I set the pressure to 1.5bar and in 24hrs it was down to 0.9bar

 

[nickso]

if primary heatex is leaking the insulation boards under it will show water damage.

 

[Adrian13]

TMC - will defo post how i get on.

Need to buy more of the F4 (see my topic thread in the forum "applying F4") as I had an issue applying. Home base appears cheapest at £15, but have none anywhere in my area. Bought from B&Q originally at £33 hence wont be going back there.

 

[Terry7556]

google screwfix to find the nearest branch to you for a more competitive price on chemicals

 

[scatmanjohn]

Good luck. If its the heat exchanger leak sealer won't work.