Radiators hot upstairs and cold downstairs..

[nickypon]

I realise this problem has been posted before but you never seem to get the outcome at the end if the thread.

I have a vented heating / hot water system in a 2 storey house with tanks in the loft and hot water cylinder on 1st floor, boiler on ground.

The house was a reposession and heating system had been previously drained and unused for 9 months

After refilling the system, i bled all radiators and switched the boiler on , radiators all become piping hot upstairs within minutes and stone cold downstairs .

I have checked the pump. Seems to be turning free and making a low vibrating noise. The pipe going in an out are both very hot.

I have bled all radiators and tried shutting of all upstairs and downstairs radiators apart from 1 downstairs to direct the flow so I could get rid if air lock if that was the problem.

None of this has worked and the boiler overheats after 5 minutes and cuts out .

Any thoughts?

 

[Howsie]

Airlock at a guess. Refill from drain off downstairs. How to do this has been covered on here before.

Good luck!

 

[stevetheplumber]

id bet on pump not working properly

 

[CXR100]

was there trv's on the downstairs one? were they closed before for the previous 9 months?? maby pins could of siezed on them! but doesent sound like it !!! sounds more like air or a blockage!

 

[SJB6]

Pump!!!! heating is only working on gravity.

 

[Iplumb123]

Yeah pump dead or seized possibly flick your heating on and go put your hand on the pump careful you don't burn yourself, does it feel like its working? No? Tap it with a hammer not too hard use the handle , still not going? replace.

 

[JCplumb]

I'm with Steve on pump.
Pumps that feel and/or sound like they're working aren't always working. The impeller can be siezed and the motor still running.

 

[Stuart0782]

I would try tuning lock shields/trv down on all rads upstairs and force flow down stairs first and rule out balancing problem first my self.

 

[Stuart0782]

After that would try and pull the rads down stairs with water vax if it is air locked some time gets it moving.

 

[michael c]

I would assume air block 1st depending on design.what size is the pipework? Are the downstairs rads on droppers ie pipes come down to each rad individually or linked into a ring?

 

[Bronze_tap]

The house was a reposession and heating system had been previously drained and unused for 9 months

I have bled all radiators and tried shutting of all upstairs and downstairs radiators apart from 1 downstairs to direct the flow so I could get rid if air lock if that was the problem.

1. PUMP - take it off and try checking that impeller rotates with the motor.
2. Try taking one of the downstairs rads off (start from the longest one) and open one side tap with hose attached until water runs clean. Do it with both sides. Also can give rad an external flush,
3. Since it is a reposession, CH probably had not been properly serviced for the last 3-5 years (since 2008), so may need some attention...