Central Heating Okay but Hot Water Not Working All aspects of plumbing questions and answers, help, tips and information

[eddiecurran]

My Central Heating is still working after draining down the system to replace a radiator. Unfortunately the hot water has not come back on, I put a sludge remover in a week ago to see if that would help unblock it. Should I simply drain down the whole system or is there something more effective I can do. By feeling the heat from the pipes coming away from the boiler I can detect pretty much where the blockage is - if the blockage is not moved by draining down is there a tool that can be pushed through the pipe to help loosen the sludge? On a couple of the joints near what appears to be the blockage there are a couple of caps (bolt shaped) that look like they could be removed. Any advice would be greatly welcomed.

[htg engineer]

More likely to be an airlock rather than sludge.

Unless there was alot of sludge when you drained down and removed the radiator.

Try draining and re-filling see if the airlock/blockage clears.

[podgeplumb]

check your motorised valve(s) are working and manually open them during draining filling. There may be a bleed point at the top of the cylinder coil that may need venting.

[eddiecurran]

Podgeplumb I am afraid you have completely lost me! I have drained down a couple of times, and also allowed it to flush through by keeping the feeder tank in the loft running. A lot of sludge came out of the system, it is running pretty clear now. The central heating is working better than ever before, but unfortunately no hot water. A couple of the larger pipes coming from the boiler, which I believe feed the hot water to heat the hot water tank, are not fully hot and go cool down along the pipe very quickly. Does this sound like a bad blockage (do systems get blocked that badly??), would it be a good idea to get those pipes taken off when the system is drained down and replaced/cleaned out, or is this likely in any way to simply make the problem worse. I don't want to screw up the heating too!

[htg engineer]

It's an airlock, if you have 4 pipes coming from boiler it's not a fully pumped system therefore you will not have any motorised valves.

Try cracking open the nuts on the flow and return at tank and see if there's any air there.

If not get a heating engineer out to pull boiler stat and it'll clear.