Central heating Pump issue

[Madrab]

Our first pump lasted 30 years. It had no issues when it was replaced at all, it was simply replaced because it was due and for a more efficient one, which likewise has run for the past 11 years with no issues at all.

.... and they were/are probably quality pumps in a reasonably clean and well maintained system?

Regardless .... I'd hate to try and count the number of pumps I have changed on systems that were either old, dirty or the pump was corroded/poor quality. The pumps were still running but they just didn't have the grunt any more to supply enough circulation to the system they may have happily run well for years.

 

[Harry Bloomfield]

Regardless .... I'd hate to try and count the number of pumps I have changed on systems that were either old, dirty or the pump was corroded/poor quality. The pumps were still running but they just didn't have the grunt any more to supply enough circulation to the system they may have happily run well for years.

But would you just invest in and slap a new pump in, without further investigation? I know I certainly would not, chucking random new parts at problem is an expensive way to diagnose a fault.

 

[Bill goodwin]

the expense of an engineer fitting a new one is a lot more expensive than me putting one in. Just trying to rule out initial problems before bringing engineer in.

 

[Madrab]

Nope, certainly wouldn't just replace it as a matter of course hence the comments below but that wasn't the initial reply. In my experience pumps can become lazy, it's not always just a case of either stop or go.

Testing by shutting off the rads upstairs as suggested is just a good temporary test to see with half the system shut down do the other rads get hot. A balancing exercise is another good procedure to go through.

I would always go through a series of test before condemning a pump. Would then check the pump to see if it could be stopped (lazy) and probably isolate and remove it for inspection. If the system was working fine and then all of a sudden it isn't and nothing else has changed, then dependent on the other test results, experience would suggest the pump would be the first place to look.

 

[oldbuffer]

If the body of the pump is hotter than the water going in to it (measured reasonably accurately, not "just by touch") then it is possible the pump's capacitor has failed. This put electrical energy through through the windings and overheats them. Capacitor is usually 5 to 8 microfarads but MUST be a motor capacitor and definitely not any other sort.

 

[pete50]

I have a similar problem to the OP. Everything has worked fine until I had a bad joint leak in a rad connection. I had lost a lot of water out of the system judging by the wetness of the underlay and the carpet. I fixed the leak but as it was a crushed olive I had to remove the joint completely, cut off the damaged olive and pipe and this resulted in even more water loss. I knew that I would have to bleed the system and I have a point on the highest part of the pipe work to do that. After I bled it, and I did get quite a bit of air out, things did not work right. Radiators were cool, hot water wasn't hot and the pump was red hot. Tried for two days to get things back to normal with successive bleeds but to no avail. I eventually bit the bullet and called in BG, we have a maintenance contract with them. Engineer arrived yesterday and spent half a day here. He dismantled the boiler (vented system incidentally) and found two faults one of which was a burner fault. I mentioned the pump but he didn't have one with him. After he had finished the rads were very hot back to how they used to be. But missus went for a bath in the evening and the water was cold and that was after the boiler had been on for at least 3 hours. I got up this morning and not trusting the water heat I switched on the immersion went for my shower, which ran cold halfway through. The rads were still very hot as they had been before the leak. at 9am everything turns off. I went to do the bit of breakfast washing up, no hot water. Turned the boiler back on just for water and the water gets hot within a half hour. Great thinks I so I turn the heating on as well. Rads are only coming up to lukewarm and water not getting hot now. Turned rads off and water gets hot. Turned water off and rads get hotter but nothing like they used to be. Boiler green "burner on" indicator is cycling on and off again.

BG engineer coming back on Monday with a pump. He isn't convinced that it is the pump and neither am I. He says there is still a lot of air in the system and he is also bringing a largish bell like gizmo that he says is a much better automatic bleeder than the maual one that is on at the moment. He will change the pump and install this bleeding gizmo thingy. We shall see how it goes. I have given up for the weekend and will have to use the little fan heater and our gas fire for heat and the immersion for water for now.

 

[Bill goodwin]

Bit of an update. Locked all the upstairs rads and the downstairs one are getting slightly warmer. Got pump today possibly old one is flagging a bit now so will see what new one does

 

[HERTS P&D]

Did you get new pump valves?

Andy

 

[Bill goodwin]

Going to check them all.thanks

 

[Madrab]

I would always ensure that you have run as many test as you can before changing the pump. Haven't actually asked is the system open vent or sealed and how large is the system?

 

[Bill goodwin]

Update. New pump fitted. All rads very hot. Appears problem solved. Thanks for all advice really appreciated.

 

[Mottie]

I do like a happy ending.

 

[HERTS P&D]

I do like a happy ending.

Watching p0rn again Mottie?



Andy

 

[Mottie]

Ha! I knew you’d have to comment on that!

 

[Bill goodwin]

Investing in new system next year.current system has seen its day. Pump is a quick fix but boiler seem better days and pipe work starting to leak. got heat for Xmas that’s main thing. Thanks everyone.