Blocked cold water pipe to heating system - advice please.........

Hi, I wondered if anyone could advise. I've just had a man round from British gas inspecting my central heating system after the radiators stopped heating. The radiators were barely getting warm, some of them not heating at all, and the upstairs ones were making trickling noises. I bled them all - then water totally stopped circulating and a loud vibrating sound could be heard which continued long after I turned the heating off.

He says the cold water inlet is blocked (sadly not covered by my 3 star maintenance - which is just my luck!) - and the pipe needs to be cut and flushed to clear it. He says it is not a big job and shouldn't cost much. Do the symptoms and diagnosis makes sense?

My question is - and not exactly being an expert on this - how much should this cost me? I am in the South East. I am concsious of being ripped off - are there any extras that could be foisted on me? Is it a straight forward job?

Many thanks for any advice.

Reply to
Steven Oakes
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Well it sounds almost identical to what we've been experiencing with our system.

We kept it going for a while by topping up the water every couple of days, via a convenient bung in the top of the bathroom towel radiator. That novelty wore off eventually though, so we turned our attention to unblocking the pipe, which we succeeded in doing eventually using somewhat unconventional techniques...

I'll stop there though as this isn't uk.bodge-it-yourself :-)

Might be worth asking why it blocked up though. One chap we had look at it (among several other amusing features of our CH system) suggested that the cold pipe routing was partly to blame (something about it dipping down before connecting into the boiler feed at the pump).

Perhaps like-for-like replacement isn't the best option?

Jim

Reply to
Jim

Thanks Jim - I'll find out what the cause was. I wonder if I can top mine up in the meantime - its a bit chilly to rely on a fan heater at the moment.........

Steve.

Reply to
Steven Oakes

Had the same happen on a couple of clients' systems, more recently this:

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to say how much it'd cost: the one above was relatively easy to get at and fix and cost just over £100 including a bottle of Sentinel boiler scale reducer, but it could take ages to find & fix and consequently cost a lot more. I'd wager more than I can afford that BG won't be your cheapest option though!

Reply to
John Stumbles

I'm visualising a 15mm pipe dropping vertically down, dipping below the circulating pipe and joining from below via two elbows and a tee. This "u" has formed a silt trap and finally healed up so the path from the tank to the system is blocked. If the pipework lends itself to "rodding" with a length of curtain wire you may be able to clear the problem in this way. If it does not you can look at an interim fix by getting hold of a Fernox or Sentinel injection vessel which is basically a pump up pressure sprayer with an adapter which screws into a radiator air vent hole instead of a lance. I would suggest you inject a bottle of a cleanser such as Sentinel Ferroquest or X400 along with a quantity of water sufficient to fill the system until the vent pipe over the F&E tank emits a little water assuring a full system. Running the heating should ensure a gradual effect by turbulence on the "plug" of sediment and may clear it without further intervention. Drain and flush the system, refill and treat with corrosion inhibitor such as Sentinel X100 If this treatment does not work you will need to (when warmer weather is here) temporarily plug the F&E tank outlet, drain the radiators, cut the elbow(s) out of the system and replace with new. Personally I would rearrange the entry of the 15mm to be at the top of the circulating pipe to avoid the "trap" causing a repeat in the future. Don't forget to remove the temporary plug from the F&E outlet. Allow about thirty pounds for an injector unit, fifteen pounds for ferroquest, another fifteen pounds for X100. If you do need to mechanically cut and renew the "u" maybe another fiver for fittings, solder etc. All plus labour if you cannot D-I-Y

Reply to
John

I should say that the only reason that worked was because the top of the towel radiator is the 2nd highest point in the system, and thus above both the blockage and the pump. Wouldn't have worked with a normal radiator (can't pour sideways anyway!).

Jim

Reply to
Jim

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