The last rad on the circuit don't warm up anymore, I replaced that and a zone valve, bled the system, but still the sucker refuses to warm up. Is it possible that the pump (20yrs old) has lost a bit of it's pumpology?, I have put my hand on the body and can feel the thing wirring away n it is on max speed.
Can a CH pump wear out?
- Thread starter DIYedboy
- Start date
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20 years old 
I think this pump has more than given its service to the heating system.
Whether or not it is your problem it think it could be time to gracefully retire it and fit a new one
Yes they can wear, scale or sludge up.
I think this pump has more than given its service to the heating system.Whether or not it is your problem it think it could be time to gracefully retire it and fit a new one
Yes they can wear, scale or sludge up.
That's an odd way of going about fault-finding.
DIYedboy, I suggest you follow the usual process of checking:-
1. Shut off the hot radiators, and see if the cold one gets hot.
2. Tell us more about your system.
3. Drain the system and gauge its health from the colour/quality of its contents.
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I don't know the terminology, but a pump does not pump as such, it can only move the water round in a sealed circuit. I know this because I thought I would be clever and use an old central heating pump to empty a fish pond attached to a hose. it didn't work.
My guess is that it becomes less efficient thereby sediment in the pipework/rads gets left behind at a slow moving spot i.e. your last radiator and restricts its flow. As the rest of the circuit is easier to flow through, thats the route it will take, the route with least resistance.
It all makes sense in my head, but putting it down on paper
it didn't work.My guess is that it becomes less efficient thereby sediment in the pipework/rads gets left behind at a slow moving spot i.e. your last radiator and restricts its flow. As the rest of the circuit is easier to flow through, thats the route it will take, the route with least resistance.
It all makes sense in my head, but putting it down on paper
Well, you've ignored my earlier advice, viz:
... so I suggest that you just go right ahead and change your pump.
Because the CH pump is a form of induction motor they will run with the same speed and torque after 20 years as when they were new.
Thats as long as the capacitor has not lost its capacity and the bearings are not tight.
However, significant wear in the bearings reduces its efficiency as does the most common degradation which is accumulations of dirt on the impeller.
I have a 15-60 iron pump circulating direct water through a boiler in a launderette which was second hand when I fitted it about 1987 ! It was still going yesterday! I hope it will work again tomorrow !
Tony
Thats as long as the capacitor has not lost its capacity and the bearings are not tight.
However, significant wear in the bearings reduces its efficiency as does the most common degradation which is accumulations of dirt on the impeller.
I have a 15-60 iron pump circulating direct water through a boiler in a launderette which was second hand when I fitted it about 1987 ! It was still going yesterday! I hope it will work again tomorrow !
Tony
Yes they do. Have been to many house's where the pump isn't capable of circulating water around the entire system due to old age. New pump fixed it on all occasions so thats enough proof for me.
To be honest i would change it as a matter of precaution anyway, why wait for it to break on christmas eve?
Saying that have seen pumps 40 years old still working, mind you the warrantee tag stated it expired in august 1975.
Sam
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