No central heating or water - oil fired system

xtremem23

Hi guys,
First post on forum so "Hello"
Just a couple of quick questions I have before I call service engineer regarding my central heating system
Yesterday, we had no heating nor hot water, turned out that the oil burner was not firing (sterling st108pl) when I looked at it I found that the high limit stat at the burner had tripped out, removed "black knob" and pushed in button, this enabled the burner to fire up and seemed to run for about 5-10mins before switching off again.
This time though it did not trip out but burner would not start again, the water jacket around the burner is warm, pipe leading to the heating pump (CP53) from the water jacket is very hot (cant hold it with my hand) but the one leading into the ground to go into house is luke warm (i.e. I can hold onto it)
All rads and water in house are cold, our system is not pressurised.
I havn't went any further with this as I thought best to seek advice from the boards, just before I call engineer out to investigate.
I'm thinking that it's possible that the CP53 pump has given up the ghost and is not pumping water to the house, whats your thoughts ?
NOTE:
Burner hasn't been service in 3 years

Pete67

Sounds like a lack of circulation, so most likely a pump problem. It may just be stuck, there should be a screw cap on the end of the pump which you can remover to gain access to the end of the shaft. See if you can turn the shaft freely with a screwdriver. You may be able to get it going this way. If that does not work you will likely need a new pump. It would also be a good time to get the burner serviced, getting the nozzle replaced, fuel pressure checked/adjusted and the burner set up with a flue gas analyser will save you more than the cost of the service.

xtremem23

The only cap that i have is a black one on the pump,when i remove it/unscrew it's just like bleed screw and water,slight bit of partial air comes out.
Is this where you think there a screw that i can manually turn the pump just to check if it actually the pump that has gone ?
This is the second pump i've put on,5 years since i last put this one on but we live in a very hard water area so i'm assuming this is probably about right.

Anything else that it cud be ?

aujopimur

Switch it on and give the pump a few taps of a hammer.

xtremem23

Haha.....the very first thing i tried was the trusty hammer method....didnt work.

Cant feel any vibration in through the pump at all but in saying that its bloody warm to feel....

Interested in finding where that screw is though to manually try n turn it befor i go and buy a new one.

If i need a new one can i just change the head by loosening the allen key bolts,or is it a complete install ?

Pete67

Assuming it's a Myson CP53, remove the black plastic cap from the center of the label end of the pump, and you should have access to the end of the shaft. A small amount of water may come out. You can give the shaft a few turns with a screwdriver to make sure it's free. If it is free, with the power on, carefully give it a flick in the direction of the arrow, and see if it starts running. If it does, but does not restart, then the capacitor has failed. You may be able to replace this without replacing the entire pump.

xtremem23

I have unscrewed the plastic cap and there was quite a bit of water coming out to be honest,seems its a bit like a bleed screw as i screwed it fully out but it does not come away from the pump to allow me to see this screw that you guys are mentioning.
I'm presuming that its not meant to by the looks of it as it seem to me to be like a stem valve,never pulled on it though.
Not 100% sure its a myson but it does say cp53,black plug is hexgon with.
When i unscrew it,it becomes looses and water/air can escape,then it goes tight again,im thinking when its tight again that this is when its trying to turn the pump perhaps which is certainly not free.
Anyone any knowledge of "Halm" pumps ?
I can get one locally here but just wonderes what their like

K.Flyer

On the old Myson pump you unscrew the the nut and as you pull it out it engages with the end of the impeller shaft to allow you to turn the shaft to free it up.
If you cannot get it to turn then most likely its had it.
Unlikely that you would find a motor with the correct impeller to match the housing, so don't waste your time doing that.
Good pumps are available for under 100€ , but it is the pump isolation valves that you may have trouble with next as old ones tend to leak having not been turned off in years.

xtremem23

Just wanted to close this thread out, i hate it when people that ask for advice dont come back and advise if and how the problem was resolved, so others can complete the same steps or tasks,gets right on my goat that does.....lol

So,anyway....in my case,the pump wudnt manually rotate,well it wud,but only if using a spanner on the black plastic knob,so obviously the pump was siezed.
New pump bought and fitted in under a cpl of hours today,so all good.

Cheers lads for the advice.

Note:
Pump nuts had to be hacksawed off.

jimf

thanks for letting us know

many times we offer free advice to people and we don't get a feed back as to what the fix was