Central heating pump replacement

[SwedishChef]

I think that my current British Gas branded central heating pump in the airing cupboard needs replacing. Recently we had the boiler replaced and ever since the bearings have sounded noisy. Yesterday it stopped pumping on speed setting 3 but restarted instantly when I switched it to 2. A couple of questions:

1. How much should I be looking at paying a local heating firm to supply and fit a replacement?
2. Are there any particular makes of pump that I should either ask for or avoid?

 

[Agile]

We would charge £84 to diagnose the problem in our local area and £65 to supply and fit a new pump of the same style by changing the head only but that would include fully checking the system and a boiler service.

If that were not possible we would charge £12 each if we had to replace the pump valves. Sometimes they dont turn off so they often have to be replaced anyway.

Some firms might charge a little less but it should not be a lot more unless there are difficult draining issues and the pump valves need changing.

Tony

 

[namsag]

Why not give the guy who changed boiler a call as boiler recently done there is a good chance he will change it jst for cost of the pump.
If not use a grundfos or a wilo as the cheaper option.
if your pump is the BG branded one with the black knob in the middle you dont want to be changing just the head as myson are about the worst pumps avialable.
Also that pump should only be on speed 1 or 2 for a normal system

 

[Agile]

Namsag is a little out of date with that pump!

Myson was bought out by Potty amnd they sold the pump part to a management buyout which had to choose a rather unmemorable name of "Circulating Pumps".

They kept the designator od CP53 ( or CP63 ) and its far easier to just change the pump head!

They are not as bad as namsag says and are used in many combi boilers all over the country.

Its easiest to change just the pump head and thats what we do!

Setting "2" should be adequate for all normal useage. They get very noisy if left on "3" !

Tony

 

[namsag]

Its still a myson pump even if it says circulating pumps on the box now and they are the worst pump out there.
What combi`s use them then tony carp sime and the old midas
And the reason for not putting them on speed thre is it then becomes equivalent of a (15/60) cp63 which is too big for standard system.

Anyone changing just the head on one of these is not thinking of there customers by giving them a quality pump such as the grundfos

 

[bengasman]

For the little bit of difference in cost, I would always go for the grundfos.
Mylos have always lasted less and wilos tend to p1ss from the centre.
If the valves work properly, and access is easy, it should be no more than call out charge plus pump, which might total up to about 120.
If the system needs draining, the pump is behind a kitchen unit under the worktop, and you have airlock problems, it could be considerably more as it then takes half a day.

 

[Agile]

What combi`s use them then tony carp sime and the old midas

The most popular that I can think of must be the Puma!

Several of the Ideals used them too.

Many others have used them in some models and for some time in others.

Tony

 

[SwedishChef]

Thanks to all for the replies - much appreciated. That's answered my original queries and tells me that the quote for a new pump from the local firm who replaced the boiler is reasonable.

Another question though - do pumps tend to work at full speed then suddenly fail, or run slower and slower before eventually failing?

The reason I ask is that some of the rads downstairs (seemingly at the end of the run) aren't getting hot (all the upstairs rads are). I turned up the boiler (Worcester Bosch Ri 24) stat last night but that made no difference in temp to the colder rads as far as I can tell. I also checked the pipes on both sides of the pump and both were very hot. The rads have all been bled recently and there is the correct amount of water in the F+E tank so I'm reasonably sure it's not caused by air in the system.

Could this be caused by?

a) the pump failing gradually?
b) a balancing problem?
c) the pump being on 2, not 3? (The plumber who replaced the boiler left the pump on 3 as he said that the rad at the very end of the run (in an extension) may not get hot if left on 2).
d) something else?

 

[Agile]

The pump can fail gradually as a result of the capacitor losing its capacitance. That can be tested with the finger test on the impeller or by measuring the value of the capacitance.

I will replace just the capacitor but few engineers even know how to test them and will just want to fit a new pump. As pumps are not that expensive thats not such a bad policy.

Pumps can also fail completely without any notice!

All normal systems should work on setting "2".

Tony

 

[SwedishChef]

Thought you might all like to know that I'm now a happy bunny - the plumber installed a new Gundfos pump and all the rads get very hot and the house now gets lovely and warm very quickly. I feel like I'm getting my monies worth out of having a new boiler now. Thanks all for the help.