My vaillant boiler won't re-pressurise even after turning the two valves

tasticz

diystarter7 said:

Hi

Sorry, not quiet following that.
Are you saying you are getting water into the combi and its reading the correct pressure?
If so, what happens after that, what do you do when you stop the water from entering boiler?

Why not take a ten minute break clear head and try after that?

I'm off to bed as I need to call New Delhi at 11am their time

Good luck I hope you get it going

No my pressure isn’t increasing when I am trying to top up the water into the system. The usual top up noise isn’t there when I turn on the valves.


boiler Is running at 0.6 bar with radiators heating except the one I took out (upstairs) which is cold/mildly hot but little to no air comes out when I bleed it.

tasticz

Ok even with radiators I have now noticed that it keeps losing pressure randomly and shows f22 error.

does this mean there might be a leak somewhere?

ThisIsWeird

0.6bar is borderline, so it's no surprise that the boiler shifts from working/not working. You can't really make any assumptions about leaks until you properly repressurise the system up to 1 or 1.2bar.

In theory you can repressurise the system pretty much anywhere, but via a rad would be the most awkward as it doesn't have a hose connector on it. So instead look for a draincock somewhere - do you know if you have one?

They should be at a low point on the pipework. Most commonly found as part of a rad valve, or on the pipework very close to a ground floor rad near a door. On more modern systems, you'll find it sticking out through the outside wall, often near the boiler - it'll likely have a hose connection on it, and a rad-key-operated !!!!!!. 

If you find this, then you can connect a garden hose to it, secure it with a jubilee clip (or it'll almost certainly blow off), and have someone controlling the garden tap... (Try and run the hose until it's full of water before connecting it.)

Demand for boiler off - Ie no CH or DHW, but you want the boiler itself on if it has a digital gauge to read.

Go to the empty rad, open both valves fully, and slacken the bleed screw. Get the garden tap turned on a small amount - a trickle. Now open the drain !!!!!! slowly and listen for the sound of water beginning to hiss through - keep it slow. Either you or someone else should check the rad for a slow, steady bleed screw hissing, AND the pressure on the gauge. You want the rad to be refilled at the slow rate the bleed screw let's out air, or else you could increase the system pressure too high, with the slight possibility of it blowing open the safety valve inside the boiler, tho' at 3bar that is extremely unlikely!

Hissss hisssss hisssss - fill it slowly until the bleed screw spurts. Close screw and draincock. Now focus on the system pressure - tweak open the draincock again until it reaches 1 bar, or fractionally above.

Happy new system pressure.

Monitor the pressure as you now use the boiler - it should ideally only fluctuate by ~0.2bar or so, but see what happens.

And almost certainly you'll need to bleed a rad again after the system has been run for a while (and the pressure could drop a wee bit, of course, so you need to have the correct top-up sorted.)

plumb1_2

Your deffo turning the 2 small levers underneath the boiler and they are in-line.

ThisIsWeird

Does yours have a short flexi-hose connecting the two valves, tasticz?

tasticz

had a boiler engineer come out today to have a look, he diagnosed it saying the problem is with one of the levers. the left side valve is blocked when you i turn both levers, nothing happens. new part ordered for replacement.

he did mention that it was nothing to do with the rads being taken out, just unfortunate of the timing. the problem was probably was there from before...

I didn't bother with re-pressuring using a hose as wanted it resolved once in for all.

i'll update how that goes once the repair is done.

macman

He didn't have a filling loop on the van, or couldn't get one from the local merchant? 

ThisIsWeird

tasticz said:

had a boiler engineer come out today to have a look, he diagnosed it saying the problem is with one of the levers. the left side valve is blocked when you i turn both levers, nothing happens. new part ordered for replacement.

he did mention that it was nothing to do with the rads being taken out, just unfortunate of the timing. the problem was probably was there from before...

I didn't bother with re-pressuring using a hose as wanted it resolved once in for all.

i'll update how that goes once the repair is done.

Good outcome, and that makes total sense.

Yes, you don't want the hassle of garden hoses when the problem has been ID'd, and a fix is on the way.

I'll remind you of inhibitor... It really comes down to how old the boiler is, or when the 'hib was last topped up. If it's been a few years, then it may already have been diminished, so the new, fresh water to refill that rad might make it too weak. It ain't worth the risk - once your internals start to corrode, it's long-term problems all the way.

The guy will probably have an 'injection' of concentrate with him, and it's 5 minutes to have it inside the rad. £25? I think it's worth it for PofM.

plumb1_2

macman said:

He didn't have a filling lop on the van, or couldn't get one from the local merchant? 

It’s not a filling loop like you think, it’s a Vaillant fill valve for Vaillant own loop and only a Vaillant part.

tasticz

Hi all just an update. 

The boiler is fully up and running.  

As plump1_2 said it was the Vaillant fill valve which was blocked (full of sludge). We did do a power flush couple months ago and the engineer said that it might be they engineer who did the power flush didn’t isolate the boiler while doing it which may have caused all this sludge from pipe work to go inside the boiler…


Anyways happy days for now