boiler very noisy, pump huming strangly

[RobArggg]

please help,

I have an open vented system,
with a glow worm fuelsaver 35F,
a comet 2 130 pump.

It has been working 'OK' for years, but some of the radiators were a bit cold at the
bottom for longer that they should be (8 rads). So I drained the system and added cleaner.

After spending lots of time bleeding radiators (and leaving for a day and doing
it again). I have a swishing,banging popping, not enough water, boiler. Also when I put the system on
heating, the pipe at the bottom of the water cylinder (outflow I guess) got hot whilst the inflow was still cold (unless I imagined this?) (the hot water heating worked fine until I added that cleaner).

The pump is making a different noise: humming in a way it has not before,
suggesting to me that it is stuck. The pump has no (obvious) bleed screw (It does not have a
big one at the end). Does it have one? ( there is a bleed point above the pump (and motor
valve)

I have tried removing the pump for inspection but the top nut is stuck HARD, and everything
but it starts to move. I have yet to try WD40 on it.

I then started to remove the 4 allen screws on the pump. Water started come out at a steady
rate, move that the volume of the pump, ie the taps leak.

What should I do next?

I think I should drain the system to below the pump, remove, inspect, replace (WD40).

Any suggestions greatfully recieved (it is cold

( yes OK I know get a new pump, new boiler..., and a plumber)

Thanks,

Rob.

 

[gas4you]

Buy yourself 2 new pump valve nuts, or 2 new pump valves.

Cut the existing nut off with a hacksaw, they cut quite easily.

Remove the pump and inspect it. But I think you know the answer as you have stated, but you shouldn't need someone in to change a pump, unless there are sever problems removing it.

Forget the WD40.