Radiator problem stage 2 Help !!

[NPD]

My Dad had a problem with two rads downstairs not heating up, so as suggested by this forum I told him to close all the lockshields on the rads working upstairs to try to get them working. This worked a treat & they started to heat up, so he then opened all the lockshields. However the next day the whole of the downstairs rads decided not to heat up (he also had put fernox reducer in the F&E tank as I had decided to help him drain down the system the following week -tomorrow).
I then advised him to remove some of the radiators that are not working & manually flush them with a hose. On replacing them he told me that they started to heat up but soon went cold - does this mean a blockage in the return pipework as they seem to be receiving a flow?
I have read numerous threads and it seems possible that it could be:
1. Pump blocked or on last legs.
2. Pipe blockage
3. System not balanced properly.
I still intend to help him drain the system as the restorer needs removing, also I think I'm right in saying that this should help remove possible sludge in the pipewok. Is the checklist above the best plan of action to resolve this problem -sorry for the novel . Any thoughts as tomorrow is doomsday !

 

[simons38]

have a look at Kamco.co.uk under power flushing, hope this helps

 

[ChrisR]

At the stage you're at I'd also remove the pump and check its impeller (remove the 2 or 4 allen screws foraccess) and its connections to the valves. Don't bother trying to operate the valves they'll leak or not work or both. Pumps do start to go slow too - a new one won't break the bank.
Let us know how it goes?