Since changing the pump the controller relays stick?!

[mattgibson]

This is a slightly strange one.

The central heating pump of 25 years old finally died so I replaced it with a grundfos one. All appeared to work fine until I noticed that the old potterton boiler was coming on and the circulation pump was running despite not being set to come on.

I replaced the drayton mid position actuator and the issue persisted. I removed the back of the water/central heating programmer to find the relay contacts stuck together.

I separated the relays and all was well for a while until it did it again. I replaced the programmer (drayton LP241)and it has done it to the replacement one also.

I separated the relay contacts again and it will switch for say 10 ten times then latch. Its like the starting current on the pump motor is damaging the controller relays.

The pump is not pulling crazy current when running and seems free to turn. but somewhere in the circuit the current is sufficient to latch the relay contacts together.

Could a failed pump capacitor be causing the start up current to latch the relay contacts together?

is there anything else in the programmer relay circuit that could be causing this issue? help!!

 

[Dan Robinson]

Can you tell us the EXACT model of pump?

Did it come with a strange extra lead?

 

[mattgibson]

Its a Grundfos UPS 2 15-50/60, but no strange extra lead?!

 

[Dan Robinson]

Call Grundfos tomorrow.


You MIGHT have suffered a glitch due to an ommission on their part.

Stand by one... With any luck more help/info to follow.

 

[Agile]

What is the make/model of your boiler?

The relays inside the LP241 are very small and not ideally suited for powering inductive loads like pumps.

Nevertheless, we don't usually hear of a problem like this.

Have you measured the current taken from the supply TO the LP241?

Tony

 

[Dan Robinson]

Tony. ?..check the CC.......relevant stuff in discussion.

OP'S boiler probably guffed by pump.


Grundfos are on shaky ground.

 

[dcawkwell]

Is it me? But surely this just points to the programmer needing replacing.
If the contacts start sticking the relay contacts are getting done.
If there is resistance between the contacts this heats up and they stick together.

 

[Dan Robinson]

Possibly. But as it's you, a Glow worm ultra what's it will probably sort it out

Hence my choice of words with regards to Grundfos.

 

[petit_pablo]

For CC members read the thread about grundfos pump heads.

For the OP - the pump head will be causing the problem. Either fit another make of pump or go back to the merchant and ask for a suppresor lead for the grundfos UPS2 pump, or ring grundfos.

The timer will be gubbed also

 

[mattgibson]

I phoned Grunfos who instantly said they had heard of this issue before and is resolved by fitting a suppressor lead. The first of these pumps were supplied without leads but due to this sort of issue the lead was issued. They have put a lead in the post, great customer service (fingers crossed it sorts it)

 

[Dan Robinson]

Are they going to cover the cost of the damaged programmers?

 

[Agile]

I phoned Grunfos who instantly said they had heard of this issue before and is resolved by fitting a suppressor lead.

I expect they read about it here!

Odd though, because I am a member of the Grundfos Pump Club and they did not email me to warn me about them!

Tony

 

[Dan Robinson]

Nor me - but they sent me a big padded envelope door to door in 24 hours full of the leads i asked for to replace customer's I installed these pumps to.

Including my own.

So far well played by Grundfos. Although they could have been a little more pro active.

Guess it is difficult for a company that doesn't products registered when installed like boiler manufacturer's do.

 

[mattgibson]

Thanks all, after calling Grunfos they sent the suppressor lead that they recommended the next day, I've just fitted it and turned the heating/hotwater on and off a few dozen times and all seems fine. It would usually permanently latch a relay within the first 10 times.

So far, no latched controller relays.

Will I ask them for the cost of the controller and midposition switch that I replaced and the fair bit of inconvenience caused? probably not. I would rather companies put their hands up admit they have a problem and help me sort it then deny they have an issue and leave me spending more to sort it myself.

Thanks again fellas,

 

[scottyboy235]

I came across this thread after encountering the exact same symptoms following fitting of a Grundfos UPS2 pump

See the following thread for my experiences:-

http://www.ukplumbersforums.co.uk/c...ssive-current-grundfos-ups2-heating-pump.html

The damages claim is still unsettled and no one is around to take any calls relating to the matter. So much for Grundfos "we'll try to help you out" promises

[17/02/14 Success. Grundfos settled the damages claim in full. Had to keep chasing them to make sure there were no problems