Boiler pressure at 0.8 after village pipe burst (UK), how long ok before topping up pressure?

[BennyK]

Yesterday a pipe in the local village/new build/neighbourhood burst. Unfortunately had some things running during this time when the water pressure dropped entirely (ie hardly any water coming out bathroom tap when turned on) due to the burst pipe in the village. After the water company fixed things in the village, our taps worked fine again but I noticed today the boiler pressure is now at 0.8 (though I hadn't been paying attention to what it was before all this). I know between 1 and 1.5 is recommended.

I looked up how to top up the pressure on an Ideal Combi boiler but was confused about whether or not you can leave the filling loop on afterwards and didn't want to do anything that would risk back contamination if I wasn't sure about it.

Also wondering, if I do top up the pressure, can the filling loop remain on or does it need to be removed after for risk of back contamination?

Is there any risk to leaving the boiler at this pressure for some time before repressurising it if I just want to wait until I can get the annual service out (which it's due for in any case) or does it need to be dealt with immediately?

 

[Burnerman]

If the pressure falls too low, the boiler may cease to operate so keep an eye on that!
On new installations I’ve seen, the filling loop has been left connected but the two taps turned fully off.....this has been both gas and oil.
Personally I’ve always disconnected the loop, but I can’t see it being essential.
John

 

[trojanhawrs]

The central heating is completely separate from the mains and the burst will have no effect on the pressure.

 

[terryplumb]

The filling loop should be removed after topping up ,but hardly ever is.
As long as the boiler fires up and provides heating and hot water there is no need to increase pressure in the short term.

 

[Justin Passing]

Many boilers keep going with the gauge at or near near zero. Best to stop looking at it......

 

[Harry Bloomfield]

Also wondering, if I do top up the pressure, can the filling loop remain on or does it need to be removed after for risk of back contamination?

Idea is, to remove it, then there is absolutely no chance of any contamination, even if both valve pass, or leak slightly.

 

[Madrab]

As other have suggested, there would normally be no direct connection between the water mains and the pressure on the boiler, as that's sealed.

I have seen some installers/repairers leaving the filling loop connected and left on, this is usually because there is a slow leak on the system somewhere and the system needs topped up more regularly than it should and they don't know/cant be bothered trying to repair it. Not suggesting that's what's going on with your system of course.

Send us a pic of the filling loop/connections on the boiler and how the valves are normally set.