Vokera Linear 24 pressure loss problem

Old 11-30-05, 07:16 AM
Visiting Guest
Posts: n/a
Vokera Linear 24 pressure loss problem

Hi all, I need some help/advice.

I have had a Vokera Linear 24 combi boiler for 4 years and am experiencing rapid pressure loss.

The boiler maintains pressure fine when the CH is on and the DHW works fine to, however when the CH is turned off the system pressure drop overnight from 1 bar cold to 0, the boiler shows red light and fault code 4, requiring me to top up the system via the filling loop and reset.

I have checked all radiators and visible pipework for leaks and have found no evidence of any, I have also bled all radiators.

The CH pipes downstairs are under the concrete floor, just under the surface, no more than 2 inches anyway.
I have very recently re-decorated the living/dining room and while I had a bare floor found no visible evidence of a leak in the form of a damp patch.

I know for the pressure to drop, water has to be escaping the system but where from?? and how much water would have to escape for the pressure to drop to 0?? would it be enough to leave a visible trace??

Is the problem more likely to be within the boiler than under the floor, ie the expansion tank or a valve of some sort and how do you test for defects, I am reasonably competent though no expert and would not attempt something beyond my ability.
If it was the expansion tank or a valve what would I need to look for.

I would much rather look at the boiler than rip up flooring and dig down into the floor to replace pipework.

Any help/advice would be really appreciated

Old 11-30-05, 02:31 PM
shacko's Avatar
Join Date: Aug 2005
Location: Baltimore County Maryland
Posts: 2,002
Upvotes: 0
Received 0 Upvotes on 0 Posts
Pressure loss

Was your decorating done on the slab where the pipes run? Did you drive anything into the slab at that time? Did the problem start at or near that time? If so thats where you need to look. FYI water will seek the path of least resistance there is no way you can be certain it would show above the slab. Best that I can do at this time.
Old 12-01-05, 01:00 AM
Visiting Guest
Posts: n/a
Thanks Shacko,
No the problem was there before I decorated, just not as bad,and nothing was done that could've penetrated one of the pipes.

Last night I tested the pressure of the Expansion Vessel and it was reading 3 psi instead of the recommended 12 psi, I re-pressurised the vessel and set the CH on the timer to fire intermitently through the night.
When I got up and checked it this morning the pressure was 0 and fault code 4 along with red light was displayed again.

I am going to check the pressure of the Expansion Vessel again now.
If this has lost pressure again could that be the problem.

I have also turned off the downstairs radiators. If the leak was downstairs would turning off the radiators stop hot water flowing downstairs, or would it still leak just the same.

I'm keeping my fingers and toes crossed that the problem is in the boiler and not the pipework.

Thanks again

Old 12-03-05, 02:24 PM
Visiting Guest
Posts: n/a
Hello again everyone,

Well I have checked the expansion vessel again after repressurisation and it has only dropped 1 psi, also the system pressure loss has increased in speed to an hour/hour and half.

There is still no visible evidence of a leak anywhere and the pressure is still fine when CH and DHW are running

Would I be right in thinking the cause of my problem must be a leak somewhere under the floor or is there still hope that there could be a fault within the boiler.

Pleeeeeeeeease someone help me out here, it's doing my nut in now

Old 12-05-05, 05:29 AM
Visiting Guest
Posts: n/a
Hi people,
Another question regarding my problem which no-one seems to have any answers to

If I have a leak in the pipework should, as the CH is running, the pressure within the system not fall faster as the water expands and gets forced out of any hole in the pipework.

Anyone have any ideas?????


Thread Tools
Search this Thread
Ask a Question
Question Title:
Your question will be posted in: