Apollo 15/30 Banging

[wobblemuffin]

Please excuse my fumblings, new to this. I have read some of the other notes which appear to relate to this but perhaps I can be precise about my problem
I have an apollo 15/30 which was shut down for a few days after which the follow happens: The boiler fires up for some 20 secs, during which there is tremendous banging and clanking then the burner stops, after some 30 secs this will start again and so on. Looking at the entries it would appear to presume a pump fault. It has a mid position valve etc. and all pipework both prior and after the pump etc. are hot to the touch.
My question is how can I test that the pump is actually turning, and, how can I be sure this fully pumped system has enough water in the system as a whole. I have bled the rads and water is obviously there. So please excuse my ignorance any help would be appreciated as some of the engineers I have utilised prior to this have been unfortunately less than expert.
Thanks in advance

 

[D_Hailsham]

I have an apollo 15/30 which was shut down for a few days

Do you mean just turned off or was the system drained as well?

It has a mid position valve etc. and all pipework both prior and after the pump etc. are hot to the touch.

If you drained the system, did you set the mid-pos valve to manual when you refilled?
Check the water level in the Feed and Expansion tank (smaller tank in the loft). When the heating is off, the level should be a couple of inches above the lower outlet.
Drain some water from the system and check the tank level drops and the ball valve opens to refill the tank.

how can I test that the pump is actually turning

Remove the large silver screw in the end of the pump (some water will trickle out so an old towel is advisable). You will see the end of the pump shaft, this can be turned with a screwdriver in the slot. It should turn easily.
Leave the silver screw off, turn the system on. You should be able to see the shaft rotating. Replace the silver screw.

A useful trick is to put the handle of a screwdriver in your ear and the sharp end against the body of the pump - you will hear the whine of the motor - try all speeds. Even if the pump is rotating, the rotor may be broken, so it is not moving the water.

 

[wobblemuffin]

D_Hailsham,

Thanks for the prompt reply, no the system was not drained, although, a chap rehung a radiator the other day and I am not sure how he did it. ie took the rad off only from valve or let it drain completely, which is why I asked my original question. I will take your advice and update you. Once again thanks very much for you input.

 

[wobblemuffin]

Update;
I check the boiler today as suggested and the following points were noted.
The level in tank is appropriate and the vale works as suggested.
The pump is free and works by hand turning.
The pump does not received any 'live' feed when the boiler starts up hence the pump does not turn.
Checking standard resistance reading across pump over-run stat is infinite, ie open circuit.

Am I to presume from this that the feed to the pump via the over-run stat, or stat are faulty.

Thanks in advance for your help

 

[Agile]

Most pump over run stats are closed to supply the pump when its hot and open when it cools down!

Tony

 

[namsag]

Rad off then rehung , makes it sound like a blocked cold feed ,water level has dropped in system on re filling the rad

 

[Agile]

But a blocked feed would not remove power to the pump!

The pump does not received any 'live' feed when the boiler starts up hence the pump does not turn.

 

[namsag]

Missed that . in that case pump over run stat , bottom right hand corner of boiler in combustion chamber , about size of a ten pence coin 2 screws hold it in place and 3 wires attached

 

[Slugbabydotcom]

A trick which many people do with these is to turn off the by pass thinking its purpose is to isolate water [wrong] then when they turn the system on they forget to open it.
Carry on with your no power to the pump theory here though. If the boiler is on and the pump isnt moving; you know theres a problem there somewhere. [usually the over run stat]
Take care if you plan on replacing it. I learnt the hard way, as usual that theres a permanent live in there. Sometimes you find this comes from a different source than the supply you turned off!

 

[Gas2Air]

And you lived to tell the tale Slug. Where was it fed from?