Biasi Riva Compact HE - losing pressure

JJ15 · 7 Jan 2007

Hi, I've very recently had the above boiler fitted. Everything worked fine for the first day. Woke up the next morning to find that the pressure gauge was showing zero. Various lights were flashing on the front of the boiler. The manual says that this is a "faulty primary circuit (no water or absence of water)". I opened the valves of the filling loop and re-pressured it to just over 1. After a day or so it was back down to zero. There are no obvious leaks around the boiler or any of the radiators. The firm who installed the boiler are coming back tomorrow to sort it out, although does anyone know why I this keeps happening?

Many thanks in advance.

Agile · 7 Jan 2007

The pressure should be set to about 1.5 when the system is cold.

It sounds as if the pressure relief valve is leaking and this should have been taken to drain away often just through the wall to the outside behind the boiler.

The PRV often leaks because there is dirt in the system. Did the installers properly power flush the system before the boiler was fitted or were they doing a cheap job?

Tony Glazier

JJ15 · 7 Jan 2007

Many thanks. I'm not sure if they did flush the system but it wasn't a cheap job. I assume that this is something they should be able to rectify when they come tomorrow?

Thanks

Agile · 7 Jan 2007

They should have power flushed the system, completed the Benchmark Certificate and notified CORGI who will in turn advise Building Control and send you a Certificate of Compliance confirming that the installer was CORGI registered.

Since CORGI have not seen the installation they are perhaps rather jumbing the gun but thats what they do. The physically inspect about 0.1% of installations but these are sometimes several visits to installers who they know are rather careless.

Tony

JJ15 · 7 Jan 2007

They were Corgi registered and said that Corgi would be notified and that I would receive a certificate from Corgi in due course. Just want to be armed with a bit of info when they come tomorrow as to the possible cause of the pressure loss!

They appeared to be very professional and had no issues when I called them to say that I was losing pressure. They are also coming to fit thermostats on each of my rads at no extra cost.

When fitting the boiler last week they also mentioned that at the same time as they fitted the thermostats, they would drain the system down (not that I really know what that means/entails) to check that everything was in working order.

Pressure seems to be maintained when the system is on, it is only when the heating goes off that after a couple of hours the pressure steadily drops.

Thanks for your advice.

Agile · 7 Jan 2007

The TRVs should be fitted as part of the installation as they are required under the energy efficiency regulations.

There should also be a room stat as well!

Did they fill in the benchmark certificate at the back of the User Manual wich comes with the boiler???

When the system is drained to fit the TRVs they should add an inhibitor when refilling, the best are Sentinel or Fernox.

Tony

JJ15 · 7 Jan 2007

Thanks. Yes I do have a room stat as well. Yes, they did fill in the benchmark cert at the back of the manual.

I have actually just checked the boiler and have lost pressure again. Therefore no heating or water again! I assume that I need to wait for it to fully cool down before re-pressurising?

Agile · 7 Jan 2007

No, you can repressurise it at any time.

It may be leaking from the PRV to the vent outside?

That can happen if they used it to drain the system and there was some dirt which became lodged under the seat.

Tony

JJ15 · 7 Jan 2007

Is there anyway that I can check this? There is no apparent leaking but I dont really know where to look!

Duzzer · 7 Jan 2007

The best way to check the Safety Blow off pipe is to go outside where flue is coming out then about 4 foot below there should be a 15mm pipe sticking out just check if it's dripping all the time or when your Central Heating has been on for a couple of hours if it's the latter its a faulty component (Expansion Vessel)

Slugbabydotcom · 8 Jan 2007

A leak on a new PRV isnt that common! I glimpsed through but couldnt see that anyone has pointed out your worst case scenario here. That is that someone has nailed a pipe or there is a leak under a floor somewhere.

JJ15 · 8 Jan 2007

Gosh, hope it isn't a leak under my concrete floors! Is it significant that I only lose pressure when the heating is off for a while? Pressure is fine when the heating is on.

Will check the blow off pipe when I get back from work.

Slugbabydotcom · 9 Jan 2007

The big question is :-
Do any of your heating pipes run under a concrete floor?

diynot

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Biasi Riva Compact HE - losing pressure

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