just a question

[spacethegas]

right can we go back a step.
your hot water is ok ?
both heating & h/w are calling ?
is the pipework going into the pump hot ?
is the pipework going out of the pump to the diverter hot ?
is the pipework going out of the diverter to the h/w cylinder hot ?
is the pipework coming out of the cylinder ( under where it goes in) back to the boiler hot ?
is the pipework leaving the diverter to the heating hot, as far as you can follow it?

 

[steved101]

is the pump vibrating/making a noise like normal? if so i can't see how it can be seized though

 

[spacethegas]

is the pump vibrating/making a noise like normal? if so i can't see how it can be seized though

its unusual, but it has been known for the spindle to break or the impeller to come adrift.

 

[steved101]

usually when a pump is worn it just doesn't heat up the water/heating quickly and is a lot slower than normal, buy as you say it could be a long shot...

if it is making a lot of vibrating noises much more than usual then it could be a possibility!

 

[JohnD]

is the pump surprisingly hot?

have you looked in the loft at the feed and expansion tank? how deep is the water in it, and is it full of mud?

if you bleed the highest radiator in the house, does water squirt out vigorously, without losing pressure, and is it black?

 

[steved101]

if the f & e cistern is either empty or full but the cold feed is blocked (due to black sludge, etc accumulated in the pipe/neutral point or bottom of the f & e cistern) then you may have your pump running dry .... but you will hae trouble with both H/W and HTG if this is the case ...

 

[JohnD]

the trouble will occur first in whichever is higher. cylinders are often mounted higher than rads so the water level may be insufficient to fill the coil. when the water level is below the pump it will all stop.

 

[shrimp]

sorry for the late reply again,but the pump is not making any noise but is very hot,but the pipes that run downwards to the valve from it are coldish and the pipes running up high are hot.
I tried the test with the valve and it seems ok.
I havent had a chances to get in the loft and check the tanks yet but will do at the weekend hopefully.

 

[JohnD]

a very hot pump usually occurs when electricity is passing through it (heating it up) and water is not passing through it (to take the heat away)

Please find out if you have enough water and tell us.

another possibility, the pump might be jammed.

there is a biggish screw in the middle of the front, if you undo this (only a drip of water will come out as this is only the casing) and squint inside with a torch, you will see a spindle with a slot in it that a screwdriver will fit.

1) did water drip out?

2) does it turn when power is supplied
if not,
3) does it turn when you turn off the power and put a screwdriver in the spindle slot.


If the pump has been running dry it is quite likely ruined.

 

[shrimp]

The tanks seem to be full the big one clean but the small one does have a fair bit of crud in the bottom,i undid the screw on the pump oin the middle of the pump and a few drips come out all be it dirty.

I couldnt get the screw out so i couldnt tell you if the spindle was going around or moving at all

 

[JohnD]

if you bleed the highest radiator in the house, does water squirt out vigorously, without losing pressure, and is it black?

What happened when you tried to take the screw out of the pump, and why were you unable to do it?

 

[shrimp]

well i undid it it had a bolt head on it water dripped out (dirty) and i tried pulling it out but it wouldnt come out and i didnt want to go and mess it up totally

 

[twgas]

probably a myson pump, try turning up pump speed to max, often gets them going, if not - pull on the bolt bit and try turning it at the same time. should turn fairly easily (with power off), if you do this when there is power to the pump it will either spin as you pull it out - motor working, or may start spinning after you turn it - pump sticking, needs replacing

 

[shrimp]

right very sorry about the late reply been very busy,anyway managed to get the bolt out but couldnt see anything in there and had a constant drip of water and the bolt had a splined end on it.
Anyway the boiler has been ok in giving us hot water all the time but still no radiators heating up.
So what are the main thing the stop the rads heating up?
And how do i check them?
Cheers for all ya help dazz

 

[doitall]

If you have thermostatic radiator valves and it hasn't been suggested take the heads off and check the pin is not stuck