Combi Boiler Pressure Increasing

mech_2

derrick wrote: »

This could be the case, although under water regs, the filling loop should be removed after pressurising;-

"A gauge is usually provided to indicate that the CH system is under pressure. It will need occasional re-pressurising from the mains water supply so a facility for a filling loop (flexible braided pipe) is provided. To comply with the water regulations the loop must be physically removed upon completion."

How does that work if my boiler has an integral filling loop?

roddydogs

espresso wrote: »

So the tap is not sealing correctly and you are slowly but continuously pressurising the system, hence your problem of building pressure

Not if the inlet tap is closed, as i assume it is!

espresso

roddydogs wrote: »

Not if the inlet tap is closed, as i assume it is!

Not necessarily due to pressure differential. Normally the same type of tap/valve is used at both ends of the filling loop. If the mains water tap/valve is leaking, it's likely that the input tap/valve, (which we know is at a system pressure of only just over 1 bar) could also leak if at mains water pressure many times higher.

derrick

mech wrote: »

How does that work if my boiler has an integral filling loop?

As far as I am aware the water regs would forbid this, as there has to be a way of disconnecting the mains water from the boiler!

cwcw

espresso wrote: »

So the tap is not sealing correctly and you are slowly but continuously pressurising the system, hence your problem of building pressure

No I don't think so. It wasn't dripping from the tap itself when disconnected, it was dripping from the disconnected hose coming from the boiler. I don't know if it was just excess or not. The hose itself and the cramped space under the boiler doesn't lend itself to being able to shake it out or anything like that.

Got home with the heating on and 1.4 pressure, so 1 day down and still ok. Think the radiator was just blocked. Fingers crossed. :beer:

espresso

cwcw wrote: »

No I don't think so. It wasn't dripping from the tap itself when disconnected, it was dripping from the disconnected hose coming from the boiler.............

Well if you left the filling loop disconnected, that would eliminate one possible cause of increased system pressure.

MissMotivation

I have recently tried bleeding my radiators, the downstairs one was fine, heard the air coming out and then a little water, the upstairs ones...which were worse....hardly any air came out and no water!

I've just read that I should top up the system too and when I looked at the pressure on the boiler it was below 1 bar and on the display it is flashing "SE". There is a key underneath the boiler which I beleive it what I need to turn to top up the system, I've tried turning this but nothing happens, however there is a valve thing next to it but when I tried turning this I heard water coming into the boiler but water also staring dripping out of the bottom of the boiler.

I really don't want to call out anyone if I can help it. Can anyone help?

MissMotivation

Sorry......having several "blonde" moments today! Meant to start a new thread!

cwcw

Update - since my last post the pressure was starting to creep up to 1.4 when cold instead of 1.3. I know 0.1 isn't much of an increase in over a month, but it's the fact that it was increasing when, if anything, one would expect a slight decrease over time.

So anyway, I tried disconnecting the hose again, and it diagnosed a problem (probably a separate one). The tap wasn't leaking, but as I mentioned earlier, the hose from the tap to the boiler was dripping. I left this over night, dripping into a tin, and by morning the tin was full! The pressure had dropped to around 0.3 (and so the heating couldn't come on this morning) from 1.4 the night before. This was over around 7 hours. So, I reconnected the hose and topped the boiler up with the tap back to 1.3, and it's all working fine again. The thing is, it's only the fact that the filling hose is connected that's stopping the leak!!

I don't know if this explains, is related to, or is completely different to the slightly increasing pressure over time. Does anyone have any ideas please?

espresso

cwcw wrote: »

Update - since my last post the pressure was starting to creep up to 1.4 when cold instead of 1.3. I know 0.1 isn't much of an increase in over a month, but it's the fact that it was increasing when, if anything, one would expect a slight decrease over time.

So anyway, I tried disconnecting the hose again, and it diagnosed a problem (probably a separate one). The tap wasn't leaking, but as I mentioned earlier, the hose from the tap to the boiler was dripping. I left this over night, dripping into a tin, and by morning the tin was full! The pressure had dropped to around 0.3 (and so the heating couldn't come on this morning) from 1.4 the night before. This was over around 7 hours. So, I reconnected the hose and topped the boiler up with the tap back to 1.3, and it's all working fine again. The thing is, it's only the fact that the filling hose is connected that's stopping the leak!!

I don't know if this explains, is related to, or is completely different to the slightly increasing pressure over time. Does anyone have any ideas please?

Your post has confused me! Do you not have a tap at each end of the filling loop? Which one is not leaking? The filling loop is just that and should really be removed, although they are often left in place, in your case it is masking a fault.