Boiler repressurise taking hours

Pocket10s · 27 Aug 2022 at 15:05

Hi there,

My boiler pressure went down to 0.5bar and we opened the valves correctly to re-fill the boiler.

However, its currently been around 2 hours and its only just got from 0.5bar to 1bar. I can't see anything wrong, no water is being expelled outside and I've definitely opened the right valves to re-fill the boiler.

Why is this happening? Is there anything else I should check? I've tried bleeding the radiators to get rid of any trapped air.

Thought I would ask before calling in a plumber.

fastwunz · 27 Aug 2022 at 15:14

Sounds ok to me - it can take a long time to pressurise

Pocket10s · 27 Aug 2022 at 15:16

fastwunz said:
Sounds ok to me - it can take a long time to pressurise

Really? Every video I've watched on Youtube (some with the same boiler) it happens almost instantly.

Thanks for the reply though, makes me a bit calmer.

the_dead_parrot · 27 Aug 2022 at 15:21

What is your cold water pressure out your taps like? If the pressure is really poor there won't be enough to overcome the pressure already in the system.

Possibly the valve or valves could be blocked/restricted. Are the valves built into the boiler? If so which boiler?

Turn them both off does the pressure immediately decrease? If so you may have a leak. As in your losing pressure as fast as your putting it in. Though this would normally go down to 0 not 0.5.

andy_mk3 · 27 Aug 2022 at 15:40

Shouldn't take more than a few seconds to pressurise a full system.

robj20 · 27 Aug 2022 at 15:58

Should only take seconds to top up the pressure. A full refill only takes me a few minutes.

chroniclard · 27 Aug 2022 at 16:03

Low pressure area and still only takes a few seconds to top ours up.

RobTi · 27 Aug 2022 at 16:27

really would need to know what your water pressure is like also if you have a flexible filling loop disconnect the end connected to the heating and turn it on into a bucket and see how it compares to the tap

Monkeynut · 27 Aug 2022 at 18:38

As above if it's a flexi loop, is there a kink in it anywhere?

dirtychinchilla · 27 Aug 2022 at 21:20

I don’t know the answer to your question but I immediately wondered if you had a leak. But it’s the middle of summer…why pressurise your heating now??

Werewolf · 27 Aug 2022 at 21:30

dirtychinchilla said:
I don’t know the answer to your question but I immediately wondered if you had a leak. But it’s the middle of summer…why pressurise your heating now??

Because you've noticed it's not working or is giving an error message?
Our combi won't give hot water if the pressure in the radiator side is too low, and instead tells you to pressurise it.
Also the best time to check out, and if needed get your boiler repaired is the summer, if you leave it until it's getting cold you can be waiting a while to get someone in, then waiting a long time for any parts (we had to have a failing part replaced earlier in the year, it took 6 weeks for it to be sourced, fortunately the boiler still worked).

It normally takes about 2-3 seconds to top ours up when it's dropped, but it hasn't done that in a few years.

Nemiyen · 27 Aug 2022 at 21:43

As others have said, it should pressurise in no time at all and you should see the gauge going up.

I used to think I'd over pressure the system if I turned the valve too far, it was that quick!

I'd double check you've not got one of the valves closed (ours had 2, one on the out and one on the in) or as someone else said, check the flexi hose isn't bent or kinked.

If it's holding pressure but just filling slowly then I'd guess the issue is at the filling point somewhere.

Either that or you're getting a swimming pool under your house!

andy_mk3 · 27 Aug 2022 at 22:16

Actually, at our old house I had this issue. Turned out to be the pressure dial was getting stuck! Put a new one on and it read properly, it wasn't filling up any more as it was equal to the mains pressure.