Central Heating

[bainbrig]

The ‘charging’ tap, which you can turn to let more water into the system, is stuck closed. The attached gauge is reading high - usually 3 bar, now 5.

Baxi Combi. We’ve got an engineer coming Monday, but is the high pressure a problem?

Could we lower it by bleeding a radiator of some water?

Suggestions welcome.

BillB

[New Judge]

At 5 bar I would have thought the emergency pressure relief valve would have opened by now. See if you can drain off some water from the system's drain valve. Releasing water via a bleed valve will take some time and will be messy. Are you sure the filling tap is not stuck slightly on thus increasing the amount of water (and so the pressure) in the system?

[bainbrig]

There is a dribble of water coming out of an overflow pipe in the alley.

Disinclined to attack the taps as on turning the whole system off earlier it initially wouldn’t restart (‘flame failure’).

Then, thankfully, after some praying and turning it on and off, it worked again.

I’m quite happy to keep it on full till engineer on Monday as long as that 5 bar isn’t critical.

[New Judge]

The dribble of water could be the pressure valve releasing some pressure. I must say that when I've seen one "blow" in the past it's been a gush, not a dribble.

My pressure gauge only goes up to 4 bar with the red line at 3 bar so I would suggest five is a bit high. Can you try draining some water off the system? That way you can see if it builds up again (indicating the possibility that the system may be filling). There must be a system drain cock somewhere towards its lowest point.

[-Talbot-]

Has your boiler got a visible filling loop?

[-Talbot-]

And it should not be reading 3 bar never mind 5 bar.

Somewhere between 1&2

[bainbrig]

We’ll have a look for the drain cock.

No visible filling loop.

Problem complicated by being old and sick! (Us, not the boiler).

[-Talbot-]

Then I would go for bleeding a radiator.
I can't see why bleeding a radiator is messy.

[New Judge]

"Has your boiler got a visible filling loop?"

The filling loop is usually a short flexible pipe which connects the mains to the central heating circuit. It's usually near the boiler and should be near to the "charging tap" you mention.

[New Judge]

"I can't see why bleeding a radiator is messy."

It is if you want to use it to release a substantial amount of water because that's not what they are designed for. Capturing the water, especially if the valve is on the rear of the radiator, could be problematic.

[ducksie]

Bainbrig, I had a baxi combi before, it was always easy manage but as I don't know your model, I can't comment, only to give a link to list of manuals for all models of baxi, your one should be there and maybe you will get some help from it
https://www.freeboilermanuals.com/baxi/

[ducksie]

I just opened one of the links/manuals, sorry bb, it looks more like something for someone installing a boiler, can't be too helpful I guess :(

[bainbrig]

Well, there’s no ‘visible’ loop there, just the gauge which is immediately above the charging on/off valve. The boiler’s probably nine years old.

I’ll have a look for the drain cock, but what I’m nervous of is the ‘flame failure’ again - 3 days without heat in this weather would not do us any good.

I suppose we could always pay silly money and get an emergency boiler repair man out..

[ducksie]

there is this bb, at the very end of all those diagrams
Baxi Customer Support
0344 871 1545
Opening hours
Monday - Friday, 8.00am-6.00pm
Weekends and Bank Holidays, 8.30am-2.00pm
Please note calls may be recorded for training and monitoring purposes

[bainbrig]

Ducksie, thanks but we’ve got an engineer coming Monday - that’s on contract, and they won’t come quicker, for any amount of gold!

[ducksie]

I knew you had an engineer bb, I just thought the link would help, looking at it, I see it won't and thought maybe someone in the call centre could go through things with you,sorry it was unhelpful - especially now the weather is getting so cold

[SparklyKid]

Would like to see a photo of this "charging valve"

I have only ever seen a loop filling system or a plastic key inserted underneath, push and twist to top up the pressure.

[bainbrig]

Baxi’s call centre people are nice enough, but not experts, and I’ve tried in the past to ‘talk to someone’ and not got anywhere.

Thanks for your efforts - currently the system is working, so fingers crossed.

[TonyV]

You should have one rad with a fitting that'll take a hosepipe for draining down system which you could use to relieve some water and pressure, if hosepipe not available, at least it will be quicker filling saucepans rather than using bleed valve. But on the other hand might be better leaving as is and keep praying till Monday.

[SparklyKid]

The problem with a drain cock, usually on a downstairs rad nearest an outside door, is, if not opened for a long time, the rubber washer will be stuck inside the valve body. The trick is not to fully remove the valve via the square shank, just loosen a couple of turns, widdle a small thin screwdriver up the bit the hose attaches to and free the valve. After a few years they get quite stuck.

[SparklyKid]

P.S. Good luck getting a sauce pan under the drain cock outlet, unless the pan is two to three inches tall,lol.