heating and hot water

[supaimpy]

ok guys I've got a potterton netaheat electronic boiler(gas) and this weekend i've been replacing the bathroom , so its been water off at stopcock , isolated at loft tank , basin out bath out and radiator out,

now bath n basin back in but radiator not yet back on and so time to get hot water back on.

hot taps spluttered and now have good flow, same with cold, but




no hot water and no central heating either. boiler is running so we still got gas, the pump i can hear running and it does change speed if I turn the switch, the 3 way valve moves ( watched whilst wife uses controller)


the boiler runs and then after a while the system vents to the header tank, i've bled pump at the center screw , tried refitting rad temporaily to no avail ,


any ideas?


supaimpy

 

[HarrogateGas]

Sounds like an air lock to me.

 

[supaimpy]

so whats best way to chase it out then? the only bleed valve /point seems to be on pump so where else , theres a short leg above the 3 way valve , that runs water as well.



supaimpy

 

[HarrogateGas]

Surge the pump for a while (turn it on and off)........turn pump to speed 3 and go out for the afternoon and hope its cleared it when you get back.

Try running it just on DHW then pop heating on to try to push the air into rads to be bled.


All in all it just take time sometimes.

 

[supaimpy]

well running at speed 3 hw on its venting like mad into header tank were waiting nasa to complain that we got an apollo take off in the loft. entry to cyclinder is hot return below its is stone cold is that normal?




supaimpy

 

[ACOperson]

Are there no nuts you can partially open near the top of the system? Failing that why not drain it and install some air pips at high level?

 

[Soggy_weetabix]

fairy liquid will shift it, but please dont use it as its corrosive to the system.

Ill leave it to your judgement.

David

 

[supaimpy]

ok ran hw water system for quite sometime and its still venting into the header tank, now we have warm not hot , well not hot enough to run a bath,

if i start it from cold takes less than 5 minutes to start venting. now believe or not warm water is an improvement but does everyone still think this is an air lock moving slowly around system?


should i drain entire ch system and then refill with fernox again?


its now driving water out the overflow and driving neighbours dog mad!

 

[Agile]

If the water level is correct in your header tank ( about 100 mm cold ) then it should not be coming out of the warning pipe (overflow ).

My suggestion would be to try your system on pump setting 1 and see if that stops the pumping over. If so it might clear itself in a little while.

I assume that you have not reversed the pump flow direction have you?

Tony

 

[joe-90]

This is a long shot, but did you by any chance install a mixer shower in your bathroom that takes the hot feed from the tank and the cold feed from the rising main? That will cause the hot water to be pushed back up the pipe into the expansion tank and out the overflow.


joe

 

[supaimpy]

should of said pump is on setting 1, we did occasionally get venting but not like this maybe once everycouple of months,


the pump flow ( not disturbed for probably 18mths ) is downwards towards the 3 way valve which then goes on to feed heat exchanger coil in cylinder and or rads. pump is in airing cupboard upstairs boiler is downstairs in kitchen


only work done is remove one rad (upstairs ) and turn off water to fit new bath and basin.

 

[Agile]

Is the water coming from the heating vent ( should be over the small tank ) ?

Is it coming from the hot water vent ( should be over the big tank ) ?

Vent pipes are not always installed correctly, I come across wrong ones every few months. Not because there are that many wrongly fitted but its those which give more difficult to diagnose faults and thats why I get called in.

Tony

 

[supaimpy]

its the vent over the small tank. just tried putting ch and hw together boilers now stopped running but pump is still running, the vent appears to be from the heater circiut ( from pump pipework , t before pump ) and not the hotwater cylinder which vents to the main cold water tank

thanks for your help if it was an air con or fridge system i'd be ok

 

[joe-90]

Could it be that the original circuit was piped up wrong and removing the radiator has blocked off the circuit flow and is now being pumped out the vent? Can you temporarily reinstall the rad? (which would put the system back as it was initially?)
The bathroom rad may well be connected to the water circuit.

joe

 

[supaimpy]

rad in bathroom back on . its not venting and banging as much, but hw is only luke warm notheat at all from rads pipe to pump too hot to touch and inlet to tank as well


when it vents its a rumble followed by a metallic rattle then what i presume is pipework contracting


why if the pipework is too hot to touch isn't the hw getting warmer I'm assuming all the other details such as pump direction and vent layouts are correct been in house since 1991 only ever had pump replaced and controller replaced

seemed such a simple job to replace bathroom suite now rapidily descending into a nightmare