Myson CP53 CH water pump on the way out, what to do?!

Tao81

Have a Myson CP53 water pump on an aged gas central heating system which is making a terrible racket whilst in operation, been doing this for a while. Last night when heating came on, no noise, so assumed pump had finally given up the ghost!:eek:

However, eventually it kicked back into noisey life again - but worried that may not have any heating for xmas if don't get it fixed.

The pump in question was fitted approx. 7 yrs ago by someone I knew at the time so have no idea of how much it would cost to get a plumber in to do the job?! - Anyone have any idea?

Struggling financially so was wondering if this would possibly be something I could tackle myself?!
As the 'old' friend who fitted the existing pump was not a plumber by trade - or would I be potentially courting trouble if I attempted it?

ormus

prob 100 quid plus parts. (30-80 quid)
get the same pump to make installation much easier. (lecky connections).
switch off the 240v mains!!!
simple mechanical diy job if you have the correct spanners/stilsons. you need 2 of em.
the pump has 2 valves either side to shut off the inlet/oulet.

edit...
ebay item number 350006234172

malcolm000

Have been occasions when pump doesn't seem to work - managed to fix it by manually kick starting it by inserting a screwdriver into the front slot and briefly turning in the direction of the arrow shown on the pump. Wouldn't recommend this if you aren't sure - but this manual turning may 'encourage' the pump to start/continue.

Canucklehead

Hi

Get the same pump . Use the head only by taking out the 4 hex head screws (used to be large x head) . This should fit the old body.
That will save you trying to undo the pump valve unions unless you're lucky (they are usually very tight.)
If you have ball type pump valves, screw slot. (as opposed to gate type) they will almost certainly leak when turned off .
If you need to replace the valves then forget separating the pump head.
Good luck.
http://www.blanchford.co.uk/acatalog/Pumps.html

Corgi Guy.

Tao81

In true female DIY fashion I have been putting this job off.....but no longer!........Have no choice, must tackle it now, or get someone in, as the pump wouldn't come on last night.:eek:
I restarted it manually and it ran until timer switched heating off (albiet very noisily!!) but didn't come on spontaneously this morning!

Replacing it looks like it should be quite a straightforward job (as long the 50mm union nuts don't decide to dig their heals in?!)

However, the main reason I'm so reticent at just rolling up my sleeves and getting on with it, is the fear of potentially causing a flood?!
......You see, I am not sure how you know when you have turned the inlet and outlet valves off or on properly? There are no indicator dials on the valves for guidance, is this normal?
Is it simply a case of turning them the opposite way to the way the are currently sitting and they will stop turning when they reach the fully off position?

Been thinking - Would it be a better idea to drain the whole system down first in an attempt to avert a major flooding disaster if I get it wrong with these valves??

Also, I gather grudfos pumps are much better quality. Would the grundfos 15/50 be a suitable replacement for the myson cp53 (they do both the 15/50 and 15/60? ) and would it be a simple case of slotting the pump onto the same pipe fittings as the old one?

Are there any particularly good DIY/Plumbing books that illustrate this type of task is done as I am always more confidence about tackling something if I can view the various stages via good pictures beforehand!

Post is a bit long sorry! Thanks for taking the time to read.:D

ormus

most isolating valves have a slot in them. turn the slot 90 degrees. that should shut the valve. the slot shows you the direction of the water passage.
it would be much easier to get the same pump as fitted.
you can get direct replacements but make sure the seller understands the you require a direct replacement!
where the wiring etc is identical.

Tao81

Thanks for the reply Ormus, I don't see any slots, they look identical to this http://www.toolstation.com/images/library/stock/webbig/56049.jpg

Do I have to drain the system to do this job? The person who replaced the pump last time didn't, as far as I can remember, but notice a few web sites state that to change the pump you need to??
Surely as long as you have isolated the pump properly, using the inlet and outlet valves, it's fine to take the old one out and just slot in another?! That's what my logic tells me anyway???

Canucklehead

Hi

You have improved your chance of success quite a bit by having gate type valves.Look at them as thought they are taps, clockwise = off. Use a 6" adjustable spanner and nip them up quite tight.(although how tight is tight I don't know! if you know what I mean)
There is no way of knowing if they are letting by at all, it's all part of the fun.
In your situation I would take the head of the pump off (as I said previously) that way you will know which valve, if any, is letting by . If it's a serious amount then refit the head and go to plan 'b'.Drain down.
If you have a motorised valve under the pump then wrap plastic round it to keep water out of it, and have lots of towels to soak up water.

Corgi Guy.

Tao81

Yeah canucklehead - Towels are already insitu for mop ups, fortunately the motorised valve is suitable positioned not to be at risk (phew!).

That's good news about the gate type valves, I thought it looked relatively straightforward due to this set up.
When you say take the head off, you mentioned before about removing the four hex head screws, I have various large and small sets of screwdrivers, wrenches etc., etc., should I be able to find an appropriate tool to remove these screws if I rummage in these, do you think? or do I have to purchase because it is relatively specialist?

When you say clockwise off, am I right in assuming both inlet and outlet work to the same principle?

I'm so grateful to you guys. Thanks so much for your kind help :beer: ..............I'm feeling more condifent with every post, I really am.:D
I'm sure I'll soon be cocky enough to race up the loft ladder and take the job on like a real pro. ............That's after I've had my bowl of spinach and turned the mains off on the way of course!;)

There is absolutely no need to drain the system is there?

ormus

very unlikely. but if the valves do leak a bit too much, then draining the system maybe the only method.
thats why its best to have everything ready for a fast change over.
the old pump off, then asap the new pump on.

better if have a helper. nothing worse than a leak and you have to run all over the house for buckets towels etc... looking for the stopco ck!

EliteHeat

Tao81 wrote: »

There is absolutely no need to drain the system is there?

This is the only way to guarantee that you will not get any leaks.

Pump changes aren't exactly difficult but like all plumbing jobs, things can go wrong very, very quickly. As previously mentioned, the nuts can be very tight or seized completely, in which case you will need to drain down anyway.