Increase boiler pressure...

TheDean · 22 Mar 2016 at 08:06

Hi All,

I'm getting a low pressure error on the boiler. Hoping some hero on here can help me increase the pressure otherwise we're in trouble

richieu10 · 22 Mar 2016 at 08:49

on my combi boiler you insert a key into it then turn the cold water feed knob to increase pressure, the thing with all the white pipes is your underfloor heating manifold and pressure looks ok from what i can see in the photo on that, so its just the boiler pressure if you flip down the front cover on the boiler there is normally an instruction on increasing pressure. whats the make and model of the boiler google might have the instructions for the particular as each is different, if you can trace the cold water feed to the boiler it will be close to that, (not a heating engineer, just have to increase my preasure every few days as i have a slight leak at the moment) Rich

Gambisk · 22 Mar 2016 at 09:15

You will need to google instructions for your specific boiler, but it will be some combination of the black taps underneath it, but I can't say for sure which taps without knowing the specifics of your boiler.

acake · 22 Mar 2016 at 09:21

in the bottom pic
behind the red and silver valve and just below the the 2 port vale with UF on it is a small silver valve with a black handle with the silver flexi hose on it thats th e cold feed for topping up the system pressure.

also is this a new system just installed?.

acake · 22 Mar 2016 at 09:27

richieu10 said:
on my combi boiler you insert a key into it then turn the cold water feed knob to increase pressure, the thing with all the white pipes is your underfloor heating manifold and pressure looks ok from what i can see in the photo on that, so its just the boiler pressure if you flip down the front cover on the boiler there is normally an instruction on increasing pressure. whats the make and model of the boiler google might have the instructions for the particular as each is different, if you can trace the cold water feed to the boiler it will be close to that, (not a heating engineer, just have to increase my preasure every few days as i have a slight leak at the moment) Rich

how can you see the pressure with no gauge showing in any of the op,s pics???

m4cc45 · 22 Mar 2016 at 09:34

On mine it's the two black taps like in picture 1 - i have to open them both before water goes in.

Mine is a combi though.

M.

TheDean · 22 Mar 2016 at 09:48

acake said:
also is this a new system just installed?.

Amazing - thank you - will try as soon as I get home. Yes - new system.

m4cc45 said:
On mine it's the two black taps like in picture 1 - i have to open them both before water goes in.

Mine is a combi though.

M.

Both black taps currently open as shown on pic. Turning them the other way would close them, wouldn't it?

m4cc45 · 22 Mar 2016 at 09:52

On mine they're like yours. Trying to remember but I believe turning them anti-clockwise opens them.

M.

Bunka · 22 Mar 2016 at 12:40

With mine I need top open them both anti-clockwise to top up.

TheDean · 22 Mar 2016 at 13:39

m4cc45 said:
On mine they're like yours. Trying to remember but I believe turning them anti-clockwise opens them.

M.

Bunka said:
With mine I need top open them both anti-clockwise to top up.

Great – thanks guys!!! So are we agreed that I need to turn both taps underneath the boiler simultaneously with the one on the hot water cylinder?

Thebug · 22 Mar 2016 at 13:47

Not the ones under the boiler that would just cut the flow through the boiler, i think

They should be on the tank like 'acake' says

acake · 22 Mar 2016 at 14:26

Thebug said:
Not the ones under the boiler that would just cut the flow through the boiler, i think

They should be on the tank like 'acake' says

correct it would there service valves for the flow and return to the cylinder.

TheDean · 22 Mar 2016 at 14:29

acake said:
correct it would there service valves for the flow and return to the cylinder.

Top man - thank you. So just turn valve on cylinder and watch pressure go up on boiler until it reaches a good level, then close valve and restart boiler?

joeyjojo · 22 Mar 2016 at 14:34

Yep. Also be aware the pressure will go up a lot when the system is hot compared to cold, so best not to overfill it. (Although a safety valve will release excess.)

TheDean said:
Both black taps currently open as shown on pic. Turning them the other way would close them, wouldn't it?

The "wings" in line with the pipe = open, at right angles = closed (usually). You want them closed apart from when topping up.

acake · 22 Mar 2016 at 15:30

TheDean said:
Amazing - thank you - will try as soon as I get home. Yes - new system.

i can bet the pressure lose is with the underfloor heating not being bled out right.Most plumbers just fill the heating up like normal rad systems and it dose not work there will be air still left in there.It will take time to get out with the set up you have.

also imo i would have put valves on the pipes to the uf manifold so it was easier to blead out properly with mains pressure and a hose and not using the heating system at all.

NvidiaDan · 22 Mar 2016 at 18:18

joeyjojo said:
Yep. Also be aware the pressure will go up a lot when the system is hot compared to cold, so best not to overfill it. (Although a safety valve will release excess.)

The "wings" in line with the pipe = open, at right angles = closed (usually). You want them closed apart from when topping up.

You don't need to touch the valves on the boiler in the picture, they are isolation valves for the flow and return. Nothing to do with topping up the system pressure

TheDean · 28 Mar 2016 at 11:03

Huge thanks, especially to acake, - issue sorted within 20 seconds once I got home.