Second pump problem?

[vizzo]

We've lived in this 3 story largish victorian house with old cast iron radiators for about 8 years. I think the c heating system is about 12 years old. The boiler was replaced 18 months ago.
This evening a rather loud constant noise started from the system. The noise sounds as though it is coming from inside a section of wall on the second floor that has been plasterboarded. Presumably there are pipes running up inside this wall to feed the radiators on the 3rd floor.
I was able to stop the noise by turning off the thermostat on the third floor.

Would it be a reasonable guess that the noise is a second pump that has worn out, and the pump is controlled by the thermostat? If so I'm guessing its hidden inside the stud wall.

Or could it be the motorized valve be making all that noise?

Just thought I'd ask if this is likely before ripping out the wall and finding nothing there!

 

[muggles]

You know your house better than anyone on here. If the noise is coming from behind a plasterboard wall, it's time to cut an inspection hatch

 

[vizzo]

Cut a hole in the plasterboard at skirting level and looking up the inside of the wall there is a zone control valve and power switch.

When the thermostat is asking for the Heating to be on (even if the programmer is switched to "off") I get the rythmic screechy sound which gets progressively worse untill it's a constant noise.
Is this sound likely to be a zone control valve problem?

The zone controlled by the valve does not get heat, so i'm assuming the valve is stuck closed.

Tomorrow i will have to take out a fairly large area of wall to be able to get at the problem.

I don't actually need the valve to be closed - I'm assuming i can't over-ride the valve to stay in the open position? I think the valve has a lever but I seem to recall that when you switch the lever to open, when the power comes on it automatically activates it. Is that right?

If there is no alternative, rather than replacing the valve I may just remove it and then replace it with a normal short length of pipe. Any problems with that idea? I really don't want to buy a new valve which i don't intend to actually use!

 

[vizzo]

... alternatively, is it more likely that its the motor or the whole valve that needs replacing in view of the screeching sound. If its the motor, that might be easier than doing away with the valve altogether.

Advice appreciated

 

[Agile]

You don't understand how they operate!

Its a motor which opens the valve obviously. But it also acts as a relay to bring on the boiler and pump.

Even if you latch the valve open then that position does not bring on the boiler.

Even if you latch it open then if the motor is activated then it runs past the latch position and when its depowered the valve closes and is no longer latched!

I really cannot understand what kind of muppet fits a motor valve inside a wall which is then to be plastered over without any further access for maintenance or repair!

Tony

 

[DP]

Even if you latch the valve open then that position does not bring on the boiler.

Not for all valve

 

[vizzo]

Even if you latch the valve open then that position does not bring on the boiler.

The way the system is set up this valve only shuts off heat to part of the house. So, whether the boiler comes on or switches off is solely based on whether the main thermostat (not the one operating this valve) is asking for it.

Even if you latch it open then if the motor is activated then it runs past the latch position and when its depowered the valve closes and is no longer latched!

That's what i suspected but just wanted confirmation -thanks.
But what if I latched it open then disconnected it from the thermostat so that it is never depowered and caused to return to the closed position.

I really cannot understand what kind of muppet fits a motor valve inside a wall which is then to be plastered over without any further access for maintenance or repair!

sadly the muppet who did a number of things to this house that we've had to put right!

So:

1. Can I get away with taking the valve out and not replacing it as i don't need it
2. Is a screeching sound likely to be the motor do you think and what is the likerlihood i could get away with just changing the motor (£10) rather than have to drain down and fit a new valve

 

[Justin Passing]

Screeches are more often from pumps than anything else. It will probably have a speed change switch on it. Between positions it would probably go "off" too, so experiment. Or remove its power and listen, but not for long or the boiler could overheat quickly.

Ditto, try removing power to the valve head.
If you do that and latch the valve open, you may find the rads get a bit warm when other circuits (alone) should be the only ones heating.

Presumably if the pump's on floor 2 out of 3 it's not running dry?

 

[vizzo]

I thought it was going to be a second pump when i heard the screeching, but cannot find a second pump anywhere so assuming ti to be the valve.

So now i have cut a slot in the wall to enable me to reach in to the valve and the power switch supplying power to the valve.
Have switched the lever to "open" and switched the power to the valve off.

This has left me with a workable temporary solution and i can put a picture on the wall to cover the letter box size hole i had to cut to get to the valve!
The heating system works fine - no screeching, heat reaches the upstairs radiators fine. Obviously can't now switch the heat off to the upstairs radiators but I've never done that in the 8/9 years we've lived here!