In an earlier contribution to this discussion,
Crewood wrote:

The pump in the system appears to be spinning, I can feel vibration,
but the body is almost to hot to touch. All the pipes around the pump
and those coming from the boiler are hot.

The pump is marked as a Commodore 130 with a small black box on the
top that has a switch with 0 to 5 settings, the current setting is 2.
I don't see where I can check if it is actually spinning or see a
bleed screw. It has also run throughout the summer months.

The system has an hot water tank upstairs and a cold water tank in the
loft.

One radiator downstairs is getting quite warm as well as one upstairs,
the others are at best just above cold to the touch.

Anymore information I can add please let me know.

CC

I would still suspect the pump. I can't remember exactly what a Commodore
looks like - although I did have one many years ago. Many pumps have a
cover - about 1/2" in diameter, with a screwdriver slot - at the opposite
end of the pump body from the water connections. When that is removed, you
can see the end of the shaft. Maybe yours is not like that?

Does your pump have isolation valves either side? If so, you could close
those, and remove the pump without having to drain down. You could then wire
it up to a 13A plug and see whether it's rotating - since you should be able
to see the impeller. [Don't run it dry for more than a few seconds, though -
it won't like it!]

Might be an idea to get one of these http://tinyurl.com/afrw5 as a spare,
anyway.
--
Cheers,
Set Square
______
Please reply to newsgroup. Reply address is invalid.