3 way valve and pump

[ballyclover]

hi,
had a plumber round today as i have no hot water going to the radiators. the pump was new in january this year, but has began to make funny noises. the plumber thinks it may be faulty or that the valve maybe at fault thus causing air in the pump, hence the noise,

he told me to remove the header on the valve and using a spanner turn the valve.
however i am able to turn the valve with my fingers, i assume as he said use a spanner it would normally be a tight turn, so it must of sheared off, would i be right in thinking this?

the plumber has said he will carry out and work but wont be for a couple of weeks so he said as i seemed to have me head screwed on i could do it.

any help would be apprecaited

cheers

 

[seco services]

have you checked the valve motor. useally the first test to do.

 

[ballyclover]

yes, when i turn the wall thermostat up the motor turns and the pipe from the 3 way valve to the radiator gets hot, but the plumber thinks this may not be fully open

 

[seco services]

if you have central heating on only and hw off and the boiler and pump is running then the valve is opening enough to activate the micro switch. so the valve is fully open.

 

[ballyclover]

i dont get a choice of hot water or heating. Its either hot water or both when i turn the thermastat on the wall up.

all 3 sides of the valve seem to get hot, but the plumber says it may not be fully open

 

[MANDATE]

If I understand it correctly, you select CH only (which should blank off the HW port) but it allows hot water to pass to the HW side.
This suggests the valve/motor is stuck at mid point. Now it's not a stuck spindle cause you can turn that by hand, so it's either caused by a faulty motor, or it could be a faulty microswitch.
There are two sources of power supply. One from the room stat to white wire of valve. (this is to drive motor to mid point)
The second source (well there's two joined together) comes from programmer HW OFF terminal and/or the satisfied terminal of the cylinder stat goes to the grey wire of valve.
This grey is there to take over from the white when microswitch is triggered and drive motor to end of travel. If it does not do this then you're left with HW/CH.
Best action I would think is to take the head off the spindle again so you can look at the underside while you test it to see if it goes to all three positions, I suspect you'll only get two ie HW and HW/CH.

 

[ballyclover]

hi thanks for that

my timer/cpmtroller does not give me the the choice of heating only.

All my controller does it to turn the boiler on, the thermatsat on the wall if turned up opens the valve for hot water to flow to the raditors.i believe the valve opens up to allow water into the tank and radiators at the same time.I know the vavle turns by hand but not sure how far it is suppose to turn.i know it doesnt do a full turn but maybe a quarter.

thing is the valve is going to cost £75.00, the pump i can get for £40.00, but dont want to replace the wrong one

 

[MANDATE]

sorry about that! I wrongly thought you had a 3 port mid position valve.

 

[ballyclover]

actually going off my part number it is a 3 port mid valve

"Honeywell 3 Port Mid Position Valve V4073A 1039 22mm"

so how far would you expect this to turn, if i turn the thermostat up on the wall for the ch, the valve must open becasue the pipe which leads to the radiators gets hot, but the radiators do not. The plumber said maybe the valve was not fully open, but unless i know how far it is suppose to turn i dont know

 

[seco services]

the whole spindle only turns about 10mm. i would opt for an airlock.

 

[ballyclover]

10 mm seems about right, but could the thing still be sheared

i have an auto air breeder fitted so how can it be air locked?

 

[malkie]

Right so the valve is 3 port now what have you removed,the silver cover which shows the motor,all you needed to do was but it to manual and see if the rads got hot have you vented the system,then put the pump to 2 and see if it works it may be pushing over,have you a gate valve on the hot water circs,if so close it and see if the rads get hot

 

[seco services]

10 mm seems about right, but could the thing still be sheared

i have an auto air breeder fitted so how can it be air locked?

never seen one shear off, seize yes.
you'll be amazed how they can get airlocked.

 

[ballyclover]

hi okay, i moved the valve to manual, ithe pump is always on 3. I turned the hot water tank thermo to 0, to enusre it didnt call for hot water. The radiators began to get hot up stairs, after about 10 mins they stopped heating up and cooled back down to cold.Downstairs did not get hot at all, but they use to. The thermosat remind at 30

the system has a auto bleed valve, i have no idea what the gate valve is, sorry.

when i undo the bleed vavle on the pump i would say it bubbles out hot water, dont know if this is air or because of the pressure forcing it past the seal.

 

[seco services]

did you bleed the pump then the rads went cold ?
did you bleed the pump running ?