new(ish) combi boiler at 0 bar pressure

[mamaleelee]

We had a brand new central heating system installed with a combi boiler (worcester bosch) installed just over a year ago.

It was working perfectly.

And then we had some building work done which involved moving one of the radiators to a different wall.

After the radiator was moved, I visited the house (building work still happening) and the central heating was turned on ... while I was there, the boiler made some violent noises for about 5 minutes or so (so loud you couldn't even talk over it).

Then a few weeks ago I tried turning on the central heat (to acclimatise new wood flooring before fitting), and nothing was happening. The Bosch engineer came out, and said the boiler was working perfectly normally, but the thermostat box was dead (power was going to it, but it was showing nothing on the LCD display).

So he took the boiler off the thermostat and fitted a timer to the boiler so that we could run the central heat.

I noticed then that the pressure was at 1 bar, and it seemed to me that it used to be higher than that, so I asked the engineer if the pressure was okay. He said it was fine.

Well, we moved back into our house a few days ago, and hubby noticed that the pressure was on 0 bar! And now all of the radiators are full of air and when I try bleeding the ones upstairs (which were almost completely full of air; only the bottom inch or so was heating up), they bleed till about 4 inches from the top and then stop.

I'm feeling a bit panicked as we have been through a lot of pain to have brand new wood flooring and a new kitchen installed on the main floor, which is where the radiator was moved ... and I'm thinking that when the builder moved the radiator and plumbed it into its new spot on the other side of the room, he may have left a leak ...

I really don't want anyone to go through our brand new floor ...

Any advice?

Is it possible that when the engineer was out, something he did while testing the boiler could have caused what's happening now? Why might the pressure have dropped from 1 bar to 0, since the engineer left?

Thanks in advance for any good advice.

 

[oldplumber]

recharge the heating circuit via the filling loop/tap assembly to 1.5/2 bar and bleed the radiators and then topup to 1 bar again and the system should work, you said the rad had been moved and the system needs topping up again

 

[Kip]

Not your engineers fault, worked fine for a year...

Just a mixture of a few things, this is a sealed system, moving a radiator the building will have to of drained the pressure out and then re-fil. With you bleeding the rads after that you have allowed presure to escape therefor it just needs topping up again.

Worchesters are a key fill-up, should be a key to the right front underneath the boiler. Top it upto 2bar and bleed the system, then leave the pressure about 1.2bar once bled.

 

[mamaleelee]

Thanks, will try it now!!

 

[oldplumber]

Not your engineers fault, worked fine for a year...

Worchesters are a key fill-up, should be a key to the right front underneath the boiler. Top it upto 2bar and bleed the system, then leave the pressure about 1.2bar once bled.

Not all are keyed, come across lots with filling loops as customers cant cope with the key, and the older large key types are prone to failing

 

[mamaleelee]

sorry to be dense, but i can't find the key? what does it look like? is it on the right, front, underneath the boiler? any detailed info would be really helpful ... i have no idea what i'm looking for ...

thanks for the replies, it's really reassuring. i can't figure out how to top up the pressure for now, so it looks like i'll have to call out an engineer again.

but another question: the pressure is about as zero as it can be now. should i keep the central heating off until the pressure is topped up again? is it bad for the system to keep running it when there is zero pressure?

 

[oldplumber]

sorry to be dense, but i can't find the key? what does it look like? is it on the right, front, underneath the boiler? any detailed info would be really helpful ... i have no idea what i'm looking for ...

keyshould be slotted in a tray under boiler which you pop out to expose the bottom of the boiler

 

[mamaleelee]

it's a Worcester Greenstar boiler, which has a panel on the bottom third of the boiler which flips down ... i can't see anything that pops off the bottom of the boiler ...

 

[oldplumber]

your instructions will probably explain this better than i can if you are unable to find the tray which slots out underneath the boiler, the engineer should have shown you all this when the boiler was first installed, if you cant find it call him back for help

 

[mamaleelee]

ok, will have a look ... nobody showed me how to top up the pressure when the boiler was installed ... i thought perhaps i wasn't supposed to ever touch it ...

but a friend of mine told me that if it's a leak and i top up the pressure that could void my insurance??

is it poss that i do have a leak? how can i tell? the builder did run the central heating and bleed all the radiators after moving the radiator ... is it normal to be needing that again?

 

[Puddle]

if you keep topping up pressure,can become a problem and we do not really know how the builder left system
lets get system set up correctly and then monitor and see what happens
as old plumber says filling key in tray at bottom of boiler,should be there or would have thought w/b engineer would have mentioned
you should also have instruction book as boiler so new
anyway if you can not fill,get someone in filll system correctly,vent and fill all rads and see how you go,if there is a leak and it is on new pipe work,you should be covered by builders insurance anyway

IMHO

 

[mamaleelee]

sound.

thanks for the advice ... shall try it!

 

[Blackcatgas]

Like somone has said the key filling loop is an optional £15 extra and might not have been fitted so it may be a normal filling loop somwhere.

 

[mamaleelee]

The engineer visited today, and showed me the filling loop!

It was just on the pipework on the wall underneath the boiler ... there's a bendy silver hose connecting two pipes, and there is a screw in each one, and to top up the pressure I just needed to open the right side first (turning the screw 90 degrees) then the left one (also 90 degrees, counter clockwise).

I was looking for a key!

Anyway, we refilled the system, bled all radiators, and fingers crossed the pressure returns to just under 2 whenever the system is cooled and off, and it's been like that all afternoon/evening ...

So I'm thinking that sounds hopeful?!

The pressure drops a bit whenever we run hot water, and rises a bit whenever the central heating is on.

Anyway, thanks everybody for the help and encouragement ... I was dreading the thought of a leak, and the messages helped me not to panic!