Plumbing / heating advice for a total noob

[cyber69]

I'm currently having a bathroom refurb done by a plumber chap we know through reputation, and he seems a good enough chap so far. A week in and we are having the tiles put on next week and finished off hopefully.

He's had to drain the heating system off to do the pipework and it has resulted in the downstairs rads not working as they were before it was drained. He is saying that the system is quite badly affected by gunge / sludge. The house is around 20 years old and we have to my knowledge, never had to have the system power flushed.

He's fitted a Magnaclean pro 2 device just above the boiler (not a combi one) and says that this should help it keep clean and may help to unblock it but I think the rads downstairs need coming off and washing out as two of them are hot at the top and cold at the bottom but also one is completely cold.

He also mentioned something about 'balancing' them?

I'm tempted to have a go myself and take the totally cold rad off and try and wash it out or should I just leave it to him to sort out? He mentioned putting some cleaner through it when he fits the rad in the bathroom.

 

[NickK]

The type of heating circuit is important - I assume you have a hot water expansion tank up stairs and a manual balancing valve too.

Simply put- you need enough pressure through the heating to pump the water around, yet enough water rate going through the boiler to prevent it from boiling. The manual valve does this by allowing some of the water to return back to the boiler, this is exceptionally important if you fit temperature radiator valves (ensure that one radiator doesn't have one too helps).

The balancing means that all the radiators are producing enough heat for their room.. your system is probably switched on/off by a single sensor like ours. The idea is to get all the rooms heated to the same level as the room that the thermostat is in. Otherwise when the thermostated room is warm all the other will be cold or too hot..
So that's done by varying the flow of water through each radiator - balancing. It's like trying to do a maths equation in plumbing

I drained and cleaned my radiators out.. I simply repeatedly drained and filled the entire system with the last filling putting in some inhibitor. That got rid of a large portion of crap in the pipes. Over time you'll also need to vent the rads as gas builds up in them (from the rusting and from the new water).

Only thing with pressure is that if the sludge blocks.. there's no point in forcing more water at it as it's likely to break older welds that have been corroded.

You can get radiators reasonably cheaply - it may be worth just replacing it - for another 25 years of maintenance free (apart from the 5 year flushing that you should do).

PS.. the rate of heat loss in a room will differ between summer and winter (point of heat loss, heating retained etc).. so best done in early winter and then adjust accordingly.

 

[cyber69]

Update The plumber we used to have the bathroom fitted has submitted an invoice for £315 to fix the rads downstairs. This is to replace a small rad and take the three larger one's off and clean them out, refill and add inhibiter and get the system working. It does not mention a power flush though.

This week we had a british gas engineer come round to do the annual boiler service and he thinks the system needs a power flush and quoted £615 to do this.

I mentioned before that we have had a magnaclean fitted, will this eventually remove all the remaining gunge in the pipes? Or is it best to have a power flush also?

 

[Thebug]

Power flush can cause more problems with leaks best off getting the original plumber to take all your rads off and flush them out with the hose pipe. And make sure he gets the inhibitor back in when done.

£315 does seem a bit steep though depends on size of rad. Might be worth doing it yourself with a mate as it could be done for around £60 for rad and inhibitor. Oh and an afternoon labour

 

[Dave L]

£615 sounds a whole lot of cash to service and *power flush* the system, no wonder many plumbers are swanning around in Range Rover TDV8's etc