Replacing Grundfos 15-60 selectric pump

[tamz]

Before you can tell the difference between a weak pump and one which is ok you have to have felt the difference between both. If it is really easy to stop it it may indeed be the pump in which case swap the head for a replacement 15 - 60.
In any case the problem is caused by circulation or lack of it including air.

Just a thought. Is the pump wired to the boiler?

 

[cdodds2004]

u thinking no pump over run wired in, i have seen a few boilers wired up like that naughty naughty

 

[donkeeboy]

Sry gents, i missed last 2 msgs as they was on the next page! Didnt realise...

About the pump, no I have not felt the difference between a weak pump and a good one I am afraid. I can just say I can stop it pretty easy, but it does requie an amount of effort. For instance, apart from the pain, I would NOT be able to stop it with my finger for instance, its still got mopre force than that.

Yes the pump is wired into the boiler. It should all be correct and proper (and modern) it was all put in 3 yrs ago new system by professional corgi guy, and wired by professional electrician.

Cdodds, if 'pump over run' means the pump running for a few minutes after boiler fires off, then yes it does do that.

Gonna carry on bleeding it as much as possible, if it carries on E9 faulting, and I think it will, then I will replace the pump. Thanks guys.

 

[spaarks]

Your pump should last a lot longer. I installed my SMC Commodore 130 over 20 years ago and it is still pumping well and very quiet.

 

[tamz]

I installed my SMC Commodore 130 over 20 years ago and it is still pumping well and very quiet.

One of the best pumps ever made.

 

[donkeeboy]

UPDATE:

Just a kwik recap - this is not so much a problem with replacing a pump - my Worc-Bosch boiler keeps tripping out on E9 (temperature rising to fast trip out). I was lead to beleive by WorcsBosch it would be the pump, now I'm no expert but I really do not think it is the pump, it works fine between trip outs, and is only 3 years old. Therefore I have been a bit stuck, not wanting to replace part after part hoping to eventually replace the right thing.

Well anyway, I am now able to recreate the circumstances to get this intermittent fault to occur! I am very much hoping it will mean something to someone, and get me a better idea of how to pregress forward from here. OK, this is how to get the fault to happen :-

A) The central heating is ON by itself (I got a 3 port MV btw)
B) Then whilst the CH is still ON, the HW kicks in too, so now CH+HW are both ON.
C) Now whilst CH+HW both on, room temperature is reached, and CH turns OFF, so now just HW is ON.
D) Soon as C happens ((a few seconds later), the boiler takes off, starts getting really noisy, temp starts rising too fast. The fault is reproduced! E9 trip out!

I should point out that the motorised valve is moving from position to position perfectly fine, I can see it moving, and CH and HW work fine independantly, and indeed both together, except when the CH goes off whilst both CH+HW are on at the time.

What can it be? I am really very keen indeed to get this sorted now, and help will be very much appreciated indeed. Thanks in advance.

 

[Spanner2k7]

hi,
if your heating is working fine, on its own and when hot water is on, then i would suggest there is nothing wrong with the boiler or pump, if the boiler locks out when it is just hot water then this is pointing to a restriction between the motorised valve hot water side back to the boiler. Is there a manual air vent my the cylinder, if so open it to check for air. If there is no air then I would say some kind of blockage on the pipework

 

[stevetheplumber]

since both work fine indpedant or together its not boiler since it happens when the valve moves id try another 3 way valve posible the ball in the valve is loose or its sticking although i belive there is always flow thru a 3 way regardless of position another possibity is the power to pump is going of during the valve travel due to a sticking micro swith in the valve wire a test lamp to the pump supplies and see if it goes out when you recreate the fault
unlikly to be a blockage as they work at other times

 

[spaarks]

The odd thing is that the HW works ok on its own, and that the valve moves to the correct position in condition 'C'.

How about checking that the pump is still running when 'C' happens? I can't imagine why it wouldn't but it seems like something is stopping the flow to the HW coil and you seem to have eliminated the valve and the pipework.

 

[donkeeboy]

Thanks gents.

No manual vent on cylinder that I know of,. I have been bleeding the pump like crazy though (HW only 2m away) no air of any significance.

Yes the pump definitely keeps running when it trips out (stage C). It keeps running until reset.

Its all pointing towards MV, or a blockage. Neither really make any sense though. Im sure its not blocked I just drained it summer, water was very clear. MV works, all the kit is 3 yrs old. Def not pump nopr boiler though so glad I didnt replace pump.

I think I will drain it again next mild day we get.

One more thing - is it possible for MVs to get 'out of alignment' so to speak? IE moving to positions but being a bit out of whack causing something like this?

Also, if I drain the system again, should I have MV in a specific position? I guess CH+HW makes sense, but in summer I left it alone so it would have been in CH-OFF HW-OFF position. maybe that means any debris will drain into the HW loop i dont know.

Strange how it all works though most of the time, and all of the time on CH, and indeed HW. It just needs that specific sequence of things to happen to do it, and even then not always.

Its happening more and more freqently, started out once every two weeks or so, then every week, every few days, now 10 weeks on its just happened 5 times this weekend alone.

Hmm very strange. I will keep you updated as things pan out. THanks for your help everybody.