Microbore system - most new rads downstairs not working

[usdgn99mdgv]

Hope someone can help! We've just had five new rads fitted to our system. Two in upstairs bedrooms, the other three downstairs (where there were two already fitted).

Prior to these changes, all rads worked.

Now, all upstairs work, and only one of those downstairs. This is the one in the kitchen closest to where our original boiler was located (this was replaced in the summer with a new Glow-worm boiler now housed in the loft).

It's a microbore system. Our installer put "Corrosion Guard Fast Cleanse" in the boiler a week ago and suggested we shut them off upstairs and put heating on full to force through whatever is blocking. This didn't work, and actually made the boiler trip out through over heating.

Our installer is now solid booked through to March, so we need to find a way to solve the problem.

Google searches have revealed that powerflushing is an option, but at £400 is an expensive one. The other option suggested is to replace the piping down to the downstairs rads thus bypassing any blockage.

Unfortunately, it's pretty cold at the moment, and I'm really not sure what to do next! Can anyone offer any advice please?!

Thanks

 

[JPC]

if all rads have gone its probably a blocked manifold. see if u can find it somewhere...
they can get craap in them speacially sitting in the lower half and this blocks the flow/return to some rads

 

[chrishutt]

Look at manual flushing of CH system in FAQ topic.

 

[usdgn99mdgv]

I'm pretty sure that cold water flushing is what the installer was trying. Is power flush any more likely to work?

Anyone know any good reputable plumbers in the Southend area?!!!

 

[Soggy_weetabix]

ds 40 it!

do it right.

Power flushes push spreaders off, therefore no good on microbore systems.

David

 

[usdgn99mdgv]

What's ds40? Is it difficult to do?!

 

[ChrisR]

Power flushes push spreaders off

Yoowot guv? COuld you elaborate?

If the installer tried the mains to push crud out then I doubt poweflushing will work? And you need circulation to get any chems in there...

Are the downstairs rads on "drops" - ie from upstairs, individually?

 

[usdgn99mdgv]

I can answer the question about rads! They all are connected via a manifold, which I now understand to be the things that look like egg whisks! A bit more info, as we've been trying some stuff today...

We tried bleeding the downstairs rads to see what happened. Pretty clear water was coming out with good pressure from two, but on the third the pressure dropped away (after starting well).

The other thing is, I looked at the pipes that come down in to where the original boiler was - in addition to the gas supply, there are four pipes. Three of these are very hot, a fourth less so. The one that is less hot and one of the hot ones both end in a number of smaller pipes branching off that look like a whisk. The pipes off the one on the right are hot, those on the left cold. This sort of suggests to me a block between the main pipe and those branching off.

We gave the cold ones a bit of a knock with a hammer and they started to get warmer. But it only carried on so long. We then noticed the boiler had tripped again. When we went to investigate why the house was cold (and found the boiler shut off), pressure was down to 0.5 bar, so we increased it back up to 1 bar.

It's a condensing boiler, and there are two pipes to the left which end in a little red cap valve, releasing those resulting in air being expelled from one

As we stand, we're back to stage 1 - rads upstairs working, one downstairs, so whatever we did only had a temporary effect!

 

[chrishutt]

Power flushes push spreaders off

I think he means the inserts on twin-entry radiator valves. Not applicable to the vast majority of microbore systems which have normal valves.

 

[Mikeyboy]

As a different reply to powerflushing ,which if carried out correctly , is normally efficient to clear heating water system , try fernox superconcentrate ch restorer , comes complete with instructions and is easily carried out by a basic understanding of diy .