Replace Myson CP53 with Grundfoss 15/50?

[Skyhigh]

Our CP53 is on the way out, everyone online recommends Grundfoss, specifically the 15/50.

So...

Does anyone have any other recommendations for a replacement pump?

Also, are all circulating pumps the same 'size' between the inlet and outlet?

(i.e. can you 'swap out' a pump without needing extra pipework - its a modern house, only 5 years old so plenty of stop-valves everywhere, etc)


I'd appreciate any help, cheers

 

[expertgasman]

Our CP53 is on the way out, everyone online recommends Grundfoss, specifically the 15/50.

So...

Does anyone have any other recommendations for a replacement pump?

I ALWAYS use Grundfos. I can't recall changing ome that where I had installed the boiler and cleaned the system.

Also, are all circulating pumps the same 'size' between the inlet and outlet?

(i.e. can you 'swap out' a pump without needing extra pipework - its a modern house, only 5 years old so plenty of stop-valves everywhere, etc)

Yes, to both Q's, at that age

 

[misterdubya]

Use a Grundfos 15-50.

The size is the same.

Mr. W.

 

[Skyhigh]

Cheers for the help guys, I've ordered a Grundfos 15-50, with some spare valves just incase the others have siezed.

Is there any point in running a cleaner such as Fernox F3 or Sentinel x800 with the old pump (while it works) before replacing it?

(Assuming that cleaning the system will cause a load of crap to be shifted, which will then pass through the pump - which wouldn't be good for a new pump).


Looking online the steps seem to be:

1. Tie up feed tank ballcock
2. Drain some water from rads.
3. Mix cleaner into bucket - pour in feed tank.
4. Release ball cock, feeds cleaner into system
5. Run for about a day (low pump speed)
6. Drain heating system fully to remove newly shifted oxide,etc.
7. Maybe fill/empty system again it to make sure more crap is out.
8. Fill system + inhibitor

* Mix in bucker, or spend £12 on an 'additive injector' from Wickes and stick it in through a rad.


Cheers

 

[johner]

Hi Skyhigh, did the groundfos work as a good replacement? if yes, where did you buy it from?

Also did you clean the system first?

Thanks
John

 

[hazetimesfive]

i like them wilo smart pumps, cheap enough

 

[Skyhigh]

Grundfos works really well, straight swap for the old pump.

Before swapping it out I drained the system, refilled and added some Fernox F3, ran it around for a few days, drained, refilled and drained the system again to flush it out a bit. Finally refilled and added Fernox F1.

I ran the F3 cleaner with the old pump in place as I didn't want to risk damaging the new pump with any junk dislodged.

I stuck the F3 and F1 in via the header tank in the end, I couldn't find an injector to fit our tiny tiny radiator bleed valves (the tiny 'shoulder' ones smaller than 1/8th that always snap!) - only took 5 mins each time.
More of a hassle getting into the loft than anything.


To find the pump I just used Google Shopping, sorted by price and chose a good price from a seller with a decent reputation/reviews.

I actually bought it from CentralHeat.co.uk as they had them on clearance at £48, which is pretty good for a retail price.
They've got some more in, but at £80+ - which isn't a great price by comparison, so shop around!
http://www.centralheat.co.uk/grundfos-15-50-super-selectric-circulating-pump-5m-head.html


Cheers,

 

[hazetimesfive]

all pumps are a straight swap.

 

[Skyhigh]

By saying it was a straight forward replacement, I meant that I encountered no problems (e.g. stuck isolation valves, etc).

Size and pressure/flow of pumps do vary - so it's worth highlighting that the Grundfos in that model is a direct swap, no size differences, alignment issues, etc.

 

[FiremanT]

all pumps are a straight swap.

Not if it is very old,they aren't (neccesarily)

 

[johner]

Hi Skyhigh & Co, many thanks, I've ordered the pump, but realised afterwards that I forgot to mention I have a 3 story house, I ordered the 5m head. Do you think this will be ok on the high flow rate setting? Should I return it and get the 6m?

 

[johnnycnx]

Update: Johner and I attempted to replace the pump and it did not go well! The nuts above and below the pump had effectively seized and would not budge.
The force applied with the wrench has caused a small hairline crack to appear in the air jet device which is a few inches above it. (The brown material is plumbers leak putty which has stopped the dripping and the area remains dry but only with low pressure ie. no central heating switched on).

Can someone please point us in the right direction of where to get a replacement part for this area of pipework?

Many Thanks!

Untitled

• johnnycnx
• 16 Jan 2013
• 1

 

[Burnerman]

It looks like either the air separator or a pipe join to it has fractured, unfortunately.....Toolstation 75473.
John

 

[johnnycnx]

Thanks Burnerman, yep the hairline 3 / 4mm crack was right on the edge of the join / and or now what i'm reliably informed is an 'air seperator. I'll ask for the whole lot to be replaced to err on the side of caution.

Are these air seperator products in any way manufacturer specific to the heating system in use or are they all the same generic item and this one can 'plug and play' as it were into my setup?

Thanks
Johnnie

 

[Burnerman]

If the crack is hairline on the solder then an experienced solderer (?) would likely fix it in situ....so long as there isn't any water in the thing.
The one you have looks identical to the Toolstation one I mentioned.
John