hot water not heating but central heating working???

[bigd111]

I recently had a burst water pipe which meant that my system was completely drained, once the water pipe was replaced and bled i seemed to get central heating but my hot water didn't seem to be working anymore????

My pipes seem to be humming and creaking even more than normal, however a plumber came to look and seemed adamant that it wasn't an airlock but an electrical fault with the timer/programmer however we have now got this replaced and it doesn't seem to have cured it.

 

[plumbnuts]

What sort of heating system do you have? If you have a cylinder it could be that the coli has not been vented. Where was the leak and what was drained down?
Steve

 

[REDSAW]

just a quick interjestion here as , at this time, could be one of a number of things.
have you got a polystyrene lid on your c.w.s.t. as on the drain down of the system a piece or to could have broken of gone down the ffeed pipe and blocked it?.
found this doing a job at a customers house after taking of a leaking rad no hot water?. not my fault as the customer drained down. but took ages scratching ones bonce to w.t.f.

 

[bigd111]

I have a gravity water system with a pumped central heating system.

I have two water tanks in my loft a central heating and a domestic hot water, which then leads into my hot water cylinder tank, The hot water tank has 2 pipes coming out of it. The hot water cylinder tank in in one of the back bedrooms with the leak occuring at a radiator pipe at the top of the stairs.

I have a baxi bermuda back boiler.

The whole system was drained from a radiator downstairs where a hosepipe was connected to one of the pipes, and the whole system done from there, i presume this would have drained the cylinder tank as well?? All hot water taps were run during this process and this was done by an ex plumper.

 

[Bernie2]

Can't quite make out what you mean.

A stored water system with central heating usually has a cold water feed cistern in the loft of about 60 gallon's (270 litres) actual. And a smaller central heating header cistern of about 15 gallons (68 litres).

The big tank (cistern) can have two pipes coming out near the bottom, one to supply cold waret to the cylinder and the other to supply cold water to the bathroom, basin, bath and wc.

The header tank (cistern) usually has a 15mm feed into the central heating system. Its probably this that may be airlocked. But if the Plumber has checked the system and its full its obvioulsy not likely to be the cold supply.

 

[justlead1]

Hi I am reading between the lines but here goes. The gravity flow and return are probably 1" or 28 mm these feed the hot water cylinder via the baxi boiler another pair, perhaps 3/4" or 22 mm feed the rads with a pump on return or flow. If the system resembles this? The problem (as has been suggested) either the 1" flow and return have air trapped in them or the coil in the cylinder. It likely that its not the first time ( the physics of the system are fairly constant from installation) Getting rid is not always easy on gravity primaries. First check that the system is full (water level in F&E cistern is correct and no obstructions, vent the highest rads till you get water. Fire up boiler with out the pump on, moniter the movement of heat through the flow and return to cylinder, at both boiler and airing cupboard. There should be gravity circulation, if not allow the boiler to reach max temp (this may shift it) if the system starts boiling switch the pump on to get rid of the heat. If this fails, switch off, and try draining down and refilling the system, filling the system via a boiler drain off cock,hose and mains water tap can work, but this can get complicated according to experiance. Good luck

 

[bigd111]

what is the best way 2 remove air from the cw and hw

 

[garry]

try this turn on your hot water and leave your heating off crack off the flow on the cylinder this is the top one of the two on the side so that there is a drip coming out get someone to watch the flame on the boiler if i goes out turn on heating for a few minutes and then turn off again keep cheaking the pipes for heat this should only take a couple of mins and been careful when it comes through it will been very hot.