Grundfos 15-60 Pump Not Working On Correct Pump Rate

[RhysWilliam]

Hi all.

My boiler kept tripping out this morning. After having a root around I worked out that it is the pump that is causing the problem. More specifically when the pump is set to 2 or 3. Works fine when set to 1 but there is a sticker on the boiler that says pump should always be set to 3. I'm assuming this to ensure that the pump rate is sufficient.

There has been a small leak in the exchange pipe that will need repairing by our plumber but I think I can do the pump myself thus saving some money on labour. As the boiler is in next to a wall it's really difficult to have a proper look at the switch to see if it can be replaced. My assumption is that the small leak has caused some corrosion in the switch so that when it is set to 2 or 3 it is short-circuiting.

Are these switches replaceable or does the whole pump need replacing? I can't seem to find much info about the specific pump and wether the switch unit can be pulled out and isolated. And I don't want to drain the system just to 'have a look.'

Also is replacing the pump a straight forward job?

Any help much appreciated.

Boiler is an Alpha CB-24 combi-boiler.

Many thanks.

 

[Aquaheat]

Simple to replace pump head.

Turn off boiler and isolate the flow and return to the heating system and drain the boiler.

Undo the 4 allen bolts that hold the pump head in place, remove pump head and remove wiring cover and disconnect wiring.

Replace in reverse order. Your system pressure will need topping up afterwards.

You could try repairing the speed controller if you like but i really wouldn't bother for the effort TBH

Part Number from Alpha is 1.015610

There are others that you could use but I'm not going to do all the work for you

Jon

 

[easyflow]

The pump head is your easy option, don,t share the job let your engineer complete the job, he will know best.

 

[RhysWilliam]

Thanks all.

Simple to replace pump head.

Turn off boiler and isolate the flow and return to the heating system and drain the boiler.

Undo the 4 allen bolts that hold the pump head in place, remove pump head and remove wiring cover and disconnect wiring.

Replace in reverse order. Your system pressure will need topping up afterwards.

You could try repairing the speed controller if you like but i really wouldn't bother for the effort TBH

Part Number from Alpha is 1.015610

There are others that you could use but I'm not going to do all the work for you

Jon

Thanks.

Is replacing the speed controller or start capacitor not an option at all? Surely a lot more cost effective than replacing the whole pump if this is the issue?

 

[Aquaheat]

You won't find the speed controller as a spare part for these at all. You may have some luck if you strip it down and find out what is at fault with it. Not something that I would do for a customer or even recommend they do. Don't worry about the capacitor as it isn't this as it wouldn't be starting at all at any speed.

Manufacturers don't look at what is cost effective to the customer but what they can make on spare parts.

If you get your RGI to look at it he should know which pump head to use.

Jon

 

[RhysWilliam]

You won't find the speed controller as a spare part for these at all. You may have some luck if you strip it down and find out what is at fault with it. Not something that I would do for a customer or even recommend they do. Don't worry about the capacitor as it isn't this as it wouldn't be starting at all at any speed.

Manufacturers don't look at what is cost effective to the customer but what they can make on spare parts.

If you get your RGI to look at it he should know which pump head to use.

Jon

OK thanks Jon.

Cheers for P/N also but seems PlumbCentre-
http://www.plumbcenter.co.uk/product/alpha-1015610-special-pump-ups-15-60/
are charging a lot more than elsewhere-
https://www.plumbarena.co.uk/product/alpha-1015610-pump-grundfos-1560/#.VolOZLQVeCc

Am I missing something...?! Would rather stick with an exact replacement than getting a different make with same specs.

 

[Aquaheat]

Plumb centre will always be more expensive if not trade.

Just a nudge in the right direction...
http://www.euroboilerparts.co.uk/pu110-grundfos-pump-1-1560-1565-92-p.asp

Jon

 

[Gasguru]

A standard 6m Grundfoss pump head will fit....you may still be able to get one that's normally fitted to many of the Worcester models (around £70 to £80).

However, on the CB24 is is not uncommon for the casing seal to disintegrate when the chamber cover is removed. There's every chance that replacing the pump or pump head will result in many leaks from elsewhere, especially the primary heat exchanger O rings. Terrible boilers. For these reasons it's not reallly a diy option. Running the pump at speed 1 will result in poor hot water performance...needs to be 3.

 

[RhysWilliam]

A-ha! That is a nudge in the right direction!

Thanks Jon. Advice much appreciated.

 

[RhysWilliam]

A standard 6m Grundfoss pump head will fit....you may still be able to get one that's normally fitted to many of the Worcester models (around £70 to £80).

However, on the CB24 is is not uncommon for the casing seal to disintegrate when the chamber cover is removed. There's every chance that replacing the pump or pump head will result in many leaks from elsewhere, especially the primary heat exchanger O rings. Terrible boilers. For these reasons it's not reallly a diy option. Running the pump at speed 1 will result in poor hot water performance...needs to be 3.

Would that be an issue when replacing the pump? I would definitely leave the leak to our gas engineer. But as the pump is accessible by just taking off the front cover, I thought it should be as simple as draining the system and removing the pump?

Thanks.

 

[Aquaheat]

Also I will add that it's best to cover the PCB area with clingfilm or if possible remove it completely, there is every chance of loosing a bit of water when the pump head comes off so best to prevent any possible damage to it.

Come back and let us know how you get on.

Jon

 

[Aquaheat]

It's easy enough to change Rhys. There is no need to remove the combustion chamber door as everything is accessible.

Take it steady and don't go at it with a sledge hammer and you will be sound mate.

Jon

 

[Gasguru]

He'll need plenty of luck, I've lost count of the number of hex seals I've changed.

 

[RhysWilliam]

Great thanks Jon.

One last question...!- I've jumped to the conclusion that the pump is the issue. When I change the pump from 1 to 2 or 3 the electric trips. And there was a small pool of water on top of the pump when I looked at it today. So I think that water has damaged the switch. Is this an issue you have come across before? If not does it sound like this could actually be the case or is something else electrical happening when the pump kicks in at higher rate?

Thanks.

 

[DP]

A standard 6m Grundfoss pump head will fit....you may still be able to get one that's normally fitted to many of the Worcester models (around £70 to £80).

However, on the CB24 is is not uncommon for the casing seal to disintegrate when the chamber cover is removed. There's every chance that replacing the pump or pump head will result in many leaks from elsewhere, especially the primary heat exchanger O rings. Terrible boilers. For these reasons it's not reallly a diy option. Running the pump at speed 1 will result in poor hot water performance...needs to be 3.

Would that be an issue when replacing the pump? I would definitely leave the leak to our gas engineer. But as the pump is accessible by just taking off the front cover, I thought it should be as simple as draining the system and removing the pump?

Thanks.

OP, looks like good advice is given but you choose to ignore it. Doing any DIY repair on that boiler will be expensive exercise for you, that you can take for granted. Has many O rings- you disturb the pump, pipes will move, boiler will then leak- PERIOD. Good chance your plumber will side step this one

That pool of water is start of your problems- pool will get bigger moment you start tinkering with it. Boiler needs PROFESSIONAL attention.