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

tasticz

I have a vaillant eco-tec 837 boiler.

I took out a radiator to paint the room, my other radiators and hot water system was working fine during the works.

After completion, I put the radiator back where it was supposed to be, tightened the nuts , turned on the TRV and also undid the other small bolt thing (this was a mistake I believe as I should have done 1 at a time?)

This resulted in pressure dropping in the boiler to 0.2 bar. Now, my boiler won't re-pressurise even after turning the cold water flow valve and the other inlet valve. I don't hear the water going into the system like I used to before (can confirm the valve is actually turning). 

• The radiators works at 0.6 bar, all of them hot except the one I took out, which is barely hot (can confirm it is correctly turned on).

• No hot water, as soon as I open tap, the pressure drops from 0.6 bar to 0.2 bar and F22 error. 

What should I do? I think I have created an airlock in the boiler is there is such a thing. I have tried bleeding radiators but no water comes out of the one I removed. Some water comes out of the radiators upstairs but they're all hot.

Shall I drain the whole system and try re-filling it or have I messed up my boiler some how?

Please help what to do.

diystarter7

Hi OP

You sure you have nit turned the water off at the mains or the smaller unit?

Thnaks

tasticz

diystarter7 said:

Hi OP

You sure you have nit turned the water off at the mains or the smaller unit?

Thnaks

no definitely not, no one touched any of the mains or any other taps. i can confirm this as cold water and hot water taps are running fine (except no hot water and the boiler won't re-pressurise).

ThisIsWeird

You don't appear to have done anything wrong. When you replace a rad and open the valves to it, the system will attempt to refill it, and you allow this to happen by opening the rad's bleed screw, and topping up the system pressure every time it drops too far. So the only issue you actually have is that the boiler doesn't refill, and that has nothing to do with the rad having been removed.

First thing is to fully ensure you are following the correct top-up procedure - you clearly think you are doing it correctly, and most likely you are, but go over the instructions again

If you are absolutely certain you are doing this correctly, then contact Vaillant and ask what could be wrong - one of the filling valves/taps could be faulty.

One other thing, you should consider adding more inhibitor to your system as it will have been diluted by the extra fresh water being added to refill the rad. The easiest way is by injecting it in via the bleed screw.

Now, triple-check you are refilling correctly

diystarter7

tasticz said:

diystarter7 said:

Hi OP

You sure you have nit turned the water off at the mains or the smaller unit?

Thnaks

no definitely not, no one touched any of the mains or any other taps. i can confirm this as cold water and hot water taps are running fine (except no hot water and the boiler won't re-pressurise).

Ok, thanks, sorry about asking that question. but it can happen.

So you are turning both of the small levers to the right nagle and these is no sound of water going in nor are the bars rising.

Are the two levels to fill under the boiler or on those silver extensions and if so is there a kink etc?

Are the filling ie turn on/off bits little levers or screws? If screws, are you sure you are turning it the correct way?

I'm no plumber, gas safe enginer but we have had combis in our homes inc rentals for years and IMO the F22 fault is the low water and will go away once filled up

Thanks

tasticz

ThisIsWeird said:

You don't appear to have done anything wrong. When you replace a rad and open the valves to it, the system will attempt to refill it, and you allow this to happen by opening the rad's bleed screw, and topping up the system pressure every time it drops too far. So the only issue you actually have is that the boiler doesn't refill, and that has nothing to do with the rad having been removed.

First thing is to fully ensure you are following the correct top-up procedure - you clearly think you are doing it correctly, and most likely you are, but go over the instructions again

If you are absolutely certain you are doing this correctly, then contact Vaillant and ask what could be wrong - one of the filling valves/taps could be faulty.

One other thing, you should consider adding more inhibitor to your system as it will have been diluted by the extra fresh water being added to refill the rad. The easiest way is by injecting it in via the bleed screw.

Now, triple-check you are refilling correctly

Have done it many times before just unfortunte, won't work this time.

May speak with vaillant or get a boiler engineer out to get it resolved as it's doing my head in now. 

I read online about filling the radiators using a garden tap and using a hose. any idea?

tasticz

diystarter7 said:

tasticz said:

diystarter7 said:

Hi OP

You sure you have nit turned the water off at the mains or the smaller unit?

Thnaks

no definitely not, no one touched any of the mains or any other taps. i can confirm this as cold water and hot water taps are running fine (except no hot water and the boiler won't re-pressurise).

Ok, thanks, sorry about asking that question. but it can happen.

So you are turning both of the small levers to the right nagle and these is no sound of water going in nor are the bars rising.

Are the two levels to fill under the boiler or on those silver extensions and if so is there a kink etc?

Are the filling ie turn on/off bits little levers or screws? If screws, are you sure you are turning it the correct way?

I'm no plumber, gas safe enginer but we have had combis in our homes inc rentals for years and IMO the F22 fault is the low water and will go away once filled up

Thanks

no kink, definitely have rotated correctly. can I ask, do you know if I can pressurise the system using a hose pipe and my garden tap, if yes, where do I put the water into the system from? what connection do I use?

diystarter7

Hi OP

Like I said I am no plumber, gas engineer. but have had loads of looks at our boliers over the years - about what you said, I'd not do that and wait for advice from an expert.

Do you have pics of the bits you are trying to turn?

Thanks

diystarter7

Btw - do you hear water when you turn the screw/lever?
Could it be your gauge is faulty?

Have you tried just turning one lever?

tasticz

diystarter7 said:

Btw - do you hear water when you turn the screw/lever?
Could it be your gauge is faulty?

Have you tried just turning one lever?

The cold water is flowing normally when I turn on hot water side of top. I then turn on the pressurising knob which stops the water to the tap and this diverts the water into the system as intended.

however I cannot hear the water going into the system like before but the gauge is working correctly as you can confirm by the water in tap no longer coming out


i am planning to drain all water from radiator and try refill system tomorrow. If this doesn’t work then may be a time for boiler engineer? Need hot water for everything 😅😅😅

diystarter7

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