Open system not re-filling

[Bon]

Hi all.

I have recently had a new boiler installed and am now trying to re-fill the system.

When I removed the old boiler, I tried to flush the system, but after draining an amount from the F & E cistern, the water wasn't circulating past the pump.

I put this down to a blocked cold feed that would be sorted when the new boiler went in, however I now the new boiler is in, I can't seem to get the system to fill up.

It is definitely not a blocked cold feed as loosening a compression fitting near where the cold feed is results in clean water gushing out. I've tried blowing/sucking(!) down the air hose connected to the boiler bleed screw which seems to push some water through, but as soon as I stop I can hear air rushing back in/out of the hose.

Loosening the bleeds on the rads results in a little air coming out, but not much. There is a little water coming out of the downstairs rads which weren't completely drained.

Just wondering if anyone could offer any advice on how to remedy. The only things I can think of are that there's a blockage somewhere or an air-lock.

Thanks in advance for any advice!

 

[mickyg]

so who installed it then?

 

[Bon]

A lad from work, however he didn't get chance to finish it off before it was ready to be filled so I finished the pipework.

Need to get it filled so the gas can be connected up and it can be run!!

 

[Bon]

I think I'm going to try disconnecting the flow from the diverting valve and running it drain and connecting the flow in my kitchen (rad isn't connected at the moment) to the outside tap (which is check-valved) and back-flush just to see if it's a blockage.

The water dribbling out of the kitchen flow at the moment is pretty black so it could be blocked.

Can anyone offer any further pearls of wisdom??

 

[mickyg]

The whole job sounds like a bodge.

 

[Bon]

Care to elaborate on how you arrived at that conclusion Micky?

I am merely asking for people's advice on what they would do if presented with a particular problem, but thanks anyway for getting my hopes up on seeing I had a reply

 

[AlanE]

It is definitely not a blocked cold feed as loosening a compression fitting near where the cold feed is results in clean water gushing out.

'Near to cold feed' might not be near enough. The blockage normally occurs at the point the cold feed meets the system. You might need to cut away section of pipe there and either clear or replace section of pipework.

Care to elaborate on how you arrived at that conclusion Micky?

That conclusion really comes from your own description in your original post where you say

I have recently had a new boiler installed and am now trying to re-fill the system.

When I removed the old boiler, I tried to flush the system, but after draining an amount from the F & E cistern, the water wasn't circulating past the pump.

Flushing a system is carried out BEFORE the new boiler is connected and the purpose of that flush is to ensure the system is clean and free from any blockages! Yet you seem to have one.

 

[ChrisR]

From what you've said, I can't see anyone knowing what the heck you have. Telling us that something is in your kitchen, is a sign that you don't understand the problem!

 

[Bon]

Apologies for any confusion Alan.

My initial attempt at removing the system of sludge and other such gak was done when the old boiler was still in place. I realise how that reads now you've pointed it out!

I'm positive it isn't the cold feed as to check this I chopped the cold feed before it enters the flow pipework and it was running out fine.

In addition the point I referred to as "near" the cold feed is about 6 inches away.

As stated in my first post, my initial problem with flushing was diagnosed as a blocked cold feed, therefors I had assumed (wrongly I know!) that the problem would have been sorted.

My plan now is to try and isolate the boiler and flush using the mains to dislodge any debris so it doesn't end up in the boiler.

I'm also thinking it could be an air lock as when the system was drained down from it's lowest point, there was still a lot of water in the mains at high level. This could be because the pipework rises and then falls (old house, uneven floors!) which could be trapping air??

 

[Bon]

From what you've said, I can't see anyone knowing what the heck you have. Telling us that something is in your kitchen, is a sign that you don't understand the problem!

Sorry Chris, I don't understand what you've posted there at all.

I can assure you I do understand the problem though, I'm just looking for an experienced guy/gal to suggest a way of remedying it that (hopefully) doesn't involve ripping up floor boards and chopping pipes.

If you require more information, please let me know

 

[twgas]

In addition the point I referred to as "near" the cold feed is about 6 inches away

blockage will almost definately be below your cut - in the TEE - where cold feed joins system. cut it out and replace rather then trying to push it out with mains pressure.[/b]

 

[Bon]

Well, I've cut out the entire section of cold feed pipework and re-done it all.

There was no blockage in the pipework I cut out so I can only assume it's an air lock or a blockage further down the flow leg of the system.

I reconnected the heating mains with a compression fitting and loosening this results in clear water running from the flow branch of the diverting valve and the F & E tank is emptying as it should.

 

[buck51]

Bon, all you need to do is find a draincock at low level and drain off flow and return one at a time untill it runs clear of air

 

[D_Hailsham]

A lad from work

Doing a bit on the side! I bet he's not CORGI registered, which is why you need someone who is when

the gas can be connected up and it can be run!!

And when the COGI guy comes along, keep you fingers crossed that he does not insist on removing and reinstalling the boiler, flue etc.

And who will fill in the Benchmark and do the notification?

 

[Bon]

A lad from work

Doing a bit on the side! I bet he's not CORGI registered

That's where you're wrong.

Just to be clear to anyone else questioning the quality of the install as opposed to helping me out.

I work for a Building Services firm and the guy who installed the water side of the boiler is a CORGI registered operative who does such work day in day out.

He did the water side on a Saturday as a favour to help me break the back of it, but didn't get chance to finish so I said I'd finish the water side off. Obviously he has to be working for the company when doing notifiable gas work, therefore will be returning when it's ready to go, i.e. system fully installed, full of water, no leaks etc... I then employ the company I work for to come and connect the gas, flues and commission the boiler to ensure that all certificates issued are legal so when he does this I'd like to keep the visit as short as possible to keep costs down (and I know what our firm charges per hour )

Cheers for the advice Buck, I will try this before trying to use the mains to flush it as when I've opened the TRV in the kitchen (which isn't connected to the rad yet) some murky water runs out, then stops and it sounds as if air is being sucked back through the valve.