back boiler and central heating problem

[jungle]

Hope some can shed some light on this problem.

Here's the problem

The back boiler from cold, only fires up for around 3 mins and turns off, theres a setting on the boiler and it's set to max (I dont think it is to do with the gas fire) I've set the room temp thing to 30C

I've left the system on for ages, but the radiators don't get hot at all, the one closes to the boiler gets warmer but not hot to touch like radiators should do.

I have tried closing all radiators and opening only one. The one closes gets hot, all the rest are either cold or warm, but the strange thing is that you can feel the pipe on the flow and it gets really hot.

I have flush a couple of the radiators, and filled them up, but they only stay warm for a while.

The pump seems fine, as you can feel both side of the pipe and their extremely hot.

I've bled the pump.

Also how do you know which side is the lock shield, as the covers have been removed and the valve has a hole in it for the screw on both sides.

Is the hot flow pipe the lock shield ?

Thanks in advance for any help.

 

[kevplumb]

would apear your in deep s**t mate tad more info would help

 

[brumylad]

sounds like the pump is not working as well as it should.

Could be sludge in the system, pump impeller damaged etc.

I would advise checking the expansion cistern for overpumping or overflowing as this might be a root cause for corrosion and sludge. Eliminate obvious causes.

power flush and +/- new pump.

Add inhibitor.

 

[Richardk]

The lockshied is the return pipe, flow pipe only used for on/off or thermostatic valves,Make sure you have water in the small expansion tank in loft as thes are classic symptoms of ball valve sticking.Could be the boiler stat faulty.