made a mistake filling CH system

[hajima]

I have a Ariston MicroCombi 23MFFI, which is about a year old.

I live in a a small flat and only have a total of 4 radiators. I fitted new TRV's to my existing radiators 1 week ago.

I drained the entire system down prior to fitting the TRV's. Upon finishing I filled the system back up via the filling loop to 1 bar. Made a big error at this point where I was thinking that I would need to let air out of the boiler via the valve on top, which I have now learnt is the expansion vessel valve . I let all the air out through the valve and I also went round all the radiators to let air out then topped up the water so that the boiler pressure gauge read 1 bar again. I ran the heating for a few hours and kept an eye on the pressure gauge it ran at around 2 bar. Since then I have not used the heating system and the boiler is only in operation to provide DHW, which in my case for showers etc in the morning for a short period.

After 1 week I have noticed that the boiler pressure gauge has dropped by 0.2 bar. I have had a quick look to see if there are any leaks around the new TRV's I fitted but can't find anything.

I understand that I have made an error by letting the air out of the expansion vessel, but have I done any lasting damage to the system? Would this be the cause of the loss in boiler pressure? I plan to re-charge the expansion vessel tonight. I would appreciate if someone could give me some advice.

 

[Agile]

The EXV must be pressurised correctly with air for the system to operate correctly.

Follow instructions in FAQ

Tony

 

[Breesey]

'Depressurise' the system before re-charging the vessel iaw instructions..

Charge the system. Bleed the rads, re-charge the system, bleed rads etc.

Don't touch the vesel again. All should be fine.

 

[hajima]

Thanks for the reply. I will pressurise the expansion vessel tonight as instructed in the FAQ.

Do you know if I have caused any damage to the system and is this the reason why I have lost 0.2 bar of pressure over a week?

 

[hi-spec plumbing heating]

have you fitted a trv in the room where the room stat is ?

 

[hajima]

have you fitted a trv in the room where the room stat is ?

I dont have a room stat

 

[Breesey]

Is there a correctly installed by-pass valve?

 

[hajima]

Is there a correctly installed by-pass valve?

the boiler has a by pass valve fitted in

 

[Breesey]

Do as I said. Follow all instruction manuals that you have that are relevant. You can expect a small drop after a drain down, when/if you get one top it up and keep an eye on it. If it continues then you probably have a leak somewhere and, in your case, it would be reasonable to assume taht it was from one of your new TRVs.

 

[hajima]

Do as I said. Follow all instruction manuals that you have that are relevant. You can expect a small drop after a drain down, when/if you get one top it up and keep an eye on it. If it continues then you probably have a leak somewhere and, in your case, it would be reasonable to assume taht it was from one of your new TRVs.

Ok, Cheers Breesey. I am trying to think as to why I have lost 0.2 bar pressure, could be that since I filled the system last week the automatic air valve has let air out of the system?

Will re-charge the exapansion vessel as soon as I am home. Will also check the pressure release valve, but I dont think the system went over more than 2 bar when I had the CH running. I'll keep my fingers crossed and hope that I havent caused any damage through letting air out of the EV.

 

[Breesey]

[quote="hajimaOk, Cheers Breesey. I am trying to think as to why I have lost 0.2 bar pressure, could be that since I filled the system last week the automatic air valve has let air out of the system?[/quote]

That could be what is happening. Quite possibly.

Will re-charge the exapansion vessel as soon as I am home. Will also check the pressure release valve, but I dont think the system went over more than 2 bar when I had the CH running. I'll keep my fingers crossed and hope that I havent caused any damage through letting air out of the EV.

You won't have caused any damage. Just check everything and refill.

 

[hajima]

I pressurised the expansion tank to 1bar last night then filled the system up to 1bar went through the routine of bleeding radiator valves then turned on the central heating. The pump seemed to have a air lock as it seemed to struggle. I took the front panel off and had a look at the AAV, which is next to the pump on the Ariston and the top cap was screwed shut. I unscrewed half a turn and a lot of air came out. The AAV had never been opened since it was installed a year ago! After doing this had to top the system up again to get it back to 1bar. Everything seems to be working fine now. I also checked all joints on visible pipework as well as the TRV's I fitted and there does not seem to be a leak. I also had a look at the PRV pipe outside and there is no trace of water dripping out. Hopefully this would have sorted the pressure problem out. I will keep an eye on it and expect to top the sytsem up until it stabalises.

 

[Breesey]

Sounds good to me