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canuck the pro
canuck the pro, Plumber
Category: Plumbing
Satisfied Customers: 2864
Experience:  Plumber and Handyman
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Hi I have a biasi Combi boiler (4yrs old) . 3 days ago the

Customer Question

Hi I have a biasi Combi boiler (4yrs old) . 3 days ago the pressure went down to zero and the pilot light wasn't working . I asked advice on justanswer. The advice was to try pressurise it using a filing loop. I did that and it worked, I opened the valves very slowly whilst using the filing loop which brought the pressure to just over one on the gauge then shut them off, removed filing tube and replaced caps. The heating is working but I'm concerned that the pressure gauge is increasing. The valves are definitely turned off but the gauge has moved from being 2 bars after one on the gauge when I first used the filing loop to being 6 bars over one on the gauge. I.e its just over 1.5. How concerned should I be that it has risen that much over 48 hours?
Submitted: 2 years ago.
Category: Plumbing
Expert:  canuck the pro replied 2 years ago.
canuck the pro :

Hi, my name is ***** ***** I have been in the plumbing and plumbing repair field for 20 years. I will be glad to help you today. Is the pressure 6 bar or are you counting the notches on the pressure gauge and it is still below 2 bar?

JACUSTOMER-ok7agwrr- :

Sorry I meant I've counted the notches. So it was just over one and now it's just over 1.5

canuck the pro :

Has it risen any more? The only explanation I can think that it would rise after the filling loop is disconnected is that either the gauge was sticking a bit which could easily be caused by a little bit of sediment in the gauge or there was a slight blockage in the system that was restricting the pressure. Have you ever had the system flushed?

canuck the pro :

There also will be a little fluctuation in the pressure as the system expands and contracts from heating and cooling. The difference in the pressure is nothing to be concerned about. I am more concerned about the cause of the loss of pressure. Not that there is any danger but there would be a small leak somewhere that would cause the loss in pressure.

JACUSTOMER-ok7agwrr- :

It has risen by 2 notches each time I've had it on for a few hours over the past two days . I've never had it flushed but ive only moved in a few weeks ago

canuck the pro :

The pressure difference will level out as the system heats and cools. Nothing to worry about there.

canuck the pro :

Maybe a bit of a blockage in a radiator. It is recommended to have the system flushed once per year. You will get the best performance with a clean system. Scale buildup on the heat exchanger will cause poor performance if it is not cleaned over the years. It is not uncommon to not have this service done and it may not cause an issue for 10 years or it may cause some poor performance in two years.

JACUSTOMER-ok7agwrr- :

Ok so unlikely to keep rising? I ask as someone house sitting for me over Xmas so want to be sure. the fact the pressure went to zero is something I should get checked out?

canuck the pro :

It has to be that the pressure gauge has a blockage. The hole to the orifice in the pressure gauge is so small and once something gets in there the pressure will take time to get past the blockage and register. The same will happen if you lose pressure. If the pressure gauge is not giving an accurate reading but the pressure is at the target pressure it will do nothing to the system performance at all. If the pressure gauge is not working then the only negative outcome of that is there is not a convenient way to monitor the pressure. It will not cause any other issue except that there is not a gauge to read.

JACUSTOMER-ok7agwrr- :

How much approx to have the system flushed for a one bed flat and does it take a long time?

canuck the pro :

It does not take a terribly long time, maybe about 2 hours including topping the system back up. The cost would be in the £300 range.

canuck the pro :

Maybe you could even negotiate that they replace the gauge for free during the process. I am sure someone would throw a little extra service like that in if they are customer service oriented.

JACUSTOMER-ok7agwrr- :

Ok thanks for your help

canuck the pro, Plumber
Category: Plumbing
Satisfied Customers: 2864
Experience: Plumber and Handyman
canuck the pro and other Plumbing Specialists are ready to help you
Expert:  canuck the pro replied 2 years ago.
You are very welcome. If I can help any further let me know. I am glad to help. Thank you also. Mike.
Expert:  Plumberpro replied 2 years ago.
Hi . there is another explanation

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