Myson pump red hot but cool radiators

[paddyswann]

Hi - before I go any further let me admit that I have very poor knowledge of all things DIY so please forgive my ignorance!

I've been in my house for 13 years and, for the first time, on turning my CH on I noticed a problem. Two upstairs radiators are warm (not hot) but the others are cold/tepid (I gather that this may be due to hot water in the system rising). The Myson pump (not sure what make) is red hot (can only touch for a couple of seconds) but the pipes either side are only warm. When the pump is on (controlled by the thermostat) I can hear through a screwdriver a low buzzing noise.

I've tried bleeding all the rads and can't find any airlock problems and I've tried giving the pump a tap (ahem!). There is a black screw on the pump but it does not twist all the way off (either by fault or design).

Does anyone have any ideas as to what might be wrong? Could the pump need replacing or is there a problem elsewhere (and why is it so hot)?

Many thanks in advance for any help you can give.

 

[JohnD]

The pump is jammed.

It is hot because electric current is running through it but there is no water movement to carry the heat away. The pipes are cool because the water in them is not moving.

You will need a new pump fitted.
It has quite likely jammed because there is sediment circulating in the water due to corrosion. You might think about giving tthe system a chemical clean and a good flush (this is an easy and inexpensive DIY job but does take time). If money is not a problem you could have a Magnaclean fitted which will trap circulating sediment. If necessary you could have a powerflush but this costs hundreds of pounds.

If you undo the screw in the middle of the pump you may see a slot in the spindle, you can see if it will turn with a screwdriver.

 

[geoff@cetltd]

If you undo the screw in the middle of the pump you may see a slot in the spindle, you can see if it will turn with a screwdriver.

which, if that works,means you don't necessarily need a new pump

 

[corgiman]

i am probably wrong, but mysons have a hexagonal nut dont they

just turn it clockwise and then pull it out a bit and give it a spin.

 

[kevplumb]

theres right son

 

[blue.element]

Did anyone tell him to turn the elec to the pump off? Na don't bother, with the Myson pumps you can undo the hex nut by hand and watch a cartwheel of water streak across the room. The colour of the stain on the magnolia will tell you the condition of the water in the primary circuit.

 

[kevplumb]

err are you real DING

 

[blue.element]

Eh...irony....humour...?.... Better get back to my whisky: my point was that the fellow said straight out he wasn't very experienced, just thought it was a humourous way to point out the obvious. What's the matter Kevplumb, has the PCB engineer in Indonesia got your goat up?

 

[kevplumb]

err p off fella can't be bothered with pratts

Kevplumb, has the PCB engineer in Indonesia got your goat up?

dream on bonny lad forgot more than the pratt will ever know

 

[corgiman]

and dad's goat is a lazy bugger, needs a good kick to get that beast up

 

[paddyswann]

Guys, I'm bowled over by your quick responses and help (don't worry ... I did get the joke blue ).

I'll try undoing the screw tonight and see if the pump will turn. Failing that I guess it's a new pump and a water clean. Is the pump easy enough to fit for a numpty like me?

Cheers once again guys - you've made a novice very happy (and hopefully ... warm!).

P.

 

[corgiman]

depends on whether the pump isolators work
its great fun when they dont

 

[paddyswann]

Hi Corgiman - cheers for the post. What's a pump isolator when it's at home and how do I figure out if it's working? Sorry - being really dense I know!!!!!!

 

[paddyswann]

Ahhh ... unless they are the valves either side that stop the water pouring out when I take the pump off (doh!). I guess I'll know if they don't work when I get covered in ****ty water!!!

If (when!?) this happens - is it just a case of putting new ones on as quick as possible (before all the water in the system fills up the living room)?

Cheers.

P.

 

[JohnD]

It would be better to drain the system rather than flood the house.

You will get a clue about the valves not working if they don't turn. In that case buy some new valves when you buy the pump. Measure the pipes first (will be 28mm or 22mm).

If you can put up photos of the pump and valves someone will tell you how bad they usually are.

Best buy a pack of chemical cleaner and a pack of inhibitor while you're at it.

Has your system got a drain-off?

Pump valves look like

or