Can't find filling loopvalve for boiler

VonLuck

My gas boiler has stopped working all of a sudden and looking at the pressure gauge on the front it is currently at zero. My thinking is that the water needs to be re-pressurised.

Does anyone know where I might find the filling loop valve to do this? Any image I've seen shows a silver flexible pipe below the boiler, but I don't have that. I'm in an apartment block so it might be a different arrangement. Could it be in the hot press, or how can I tell which valve is for the boiler?

DGOBS

A picture of the hotpress pipework and we may be able to guide you.

VonLuck

I don't even know if I'm looking at the right pipework, but here you go!

https://imgur.com/a/zXqgdW0

John.G

Its highlighted with red circle, at left side you have a combined check and slotted isolating valve (it might be opened if slot is horizontal), at the other end is a black
isolation valve which is closed, with a cold boiler/system the pressure should be 1.25/1.5 bar.

VonLuck

John.G wrote: »

Its highlighted with red circle, at left side you have a combined check and slotted isolating valve (it might be opened if slot is horizontal), at the other end is a black
isolation valve which is closed, with a cold boiler/system the pressure should be 1.25/1.5 bar.

That's great, thanks.

I'm completely new to any of this so excuse my ignorance, but to adjust the pressure do I just open the black valve and go to my boiler and wait until the pressure reaches 1.5 bar max?

DGOBS

Yes, maybe just open in bursts of 10 seconds, dont over fill!

If you do, bleed/vent a rad back down to 1 - 1.5 bar

After you fill as part of your home maintenance, bleed/vent every rad of all air (if any present) and keep checking and topping up your pressure as you go.

If you frequently need to top up, there is an issue that will need resolving.

John.G

VonLuck wrote: »

That's great, thanks.

I'm completely new to any of this so excuse my ignorance, but to adjust the pressure do I just open the black valve and go to my boiler and wait until the pressure reaches 1.5 bar max?

If on you own then open the left hand valve fully, slot horizontal, then open right valve slowly until you hear water passing through it, shut it after maybe 10 secs and see if any increase in pressure then repeat until you have > 1.0 bar. You are far better off getting someone to watch the pressure rise while you just crack that valve open and adjust finally to 1.25/1.5 bar.

VonLuck

DGOBS wrote: »

Yes, maybe just open in bursts of 10 seconds, dont over fill!

If you do, bleed/vent a rad back down to 1 - 1.5 bar

After you fill as part of your home maintenance, bleed/vent every rad of all air (if any present) and keep checking and topping up your pressure as you go.

If you frequently need to top up, there is an issue that will need resolving.

That's great, thanks for the help. The boiler is back working now.

I accidentally went to 1.6 bar because of the way the gauge was behaving. It would rise and then drop slightly after the valve closed. Didn't realise the drop would be lower as the pressure increased and overshot slightly.

Is this a problem or what might happen if it stays at 1.6?

Wheety

Is it still within the green section on the guage?

VonLuck

Wheety wrote: »

Is it still within the green section on the guage?

There's no green section. There's a lower and upper section which is red, and someone marked the gauge at 1.5 bar with a black marker.

It's actually risen in pressure to 2 bar now for some reason! I did just have the gas on to heat some water. Would that have cause a temporary increase?

DGOBS

1.6 will be fine, it will increase when the water in the system is hot, 0.5-1 bar increase is ok
When boiler is off and water cools it will go back to 1.6

(technically you only need 0.5 bar pressure per storey)

VonLuck

DGOBS wrote: »

1.6 will be fine, it will increase when the water in the system is hot, 0.5-1 bar increase is ok
When boiler is off and water cools it will go back to 1.6

(technically you only need 0.5 bar pressure per storey)

For my own curiosity, does the water pressure have any effect on the efficiency of a boiler? Say if it was below 0.5 bar, would that cause a reduced flow and therefore longer to heat the same volume of water to the required temperature?

John.G

VonLuck wrote: »

For my own curiosity, does the water pressure have any effect on the efficiency of a boiler? Say if it was below 0.5 bar, would that cause a reduced flow and therefore longer to heat the same volume of water to the required temperature?

No, no effect on efficiency, as stated above, minimum pressure has to be equal to or slightly higher than the static height of the highest rad and most boiler water pressure trips are - 0.5 bar = a height of 5 M.