Pump Running, bolier always on, motorised valves - HELP!!!!

[bucherdi]

Even if the programmer is off for both water and heating, if I turn the boiler stat up until it clicks, the boiler lights. The heating doesn't get hot but I assume it's heating the water. The pump in the airing cupboard is also on all the time, even if I turn the boiler stat all the way down so the boiler turns off. After investigation, I discovered a box next to the pump with a label on it that says 'valve actuator'. On top of this box is a switch which appears to be generally to the right. While the pump was playing up, I moved the switch to the left, it moved itself back and the problem goes away for a couple of days, only to return later. The more astute among you may have spotted my heating engineering skills are not my strong point so any (simple) words of advice would be appreciated - ie. what do I need to buy???
Thanks
Dave

 

[Softus]

what do I need to buy?

The services of a heating engineer, because your system sounds as though it has been incorrectly installed.

At best it's been wrongly wired, but that might not be all.

You can get more advice here of course, but you'll need to supply all the information requested here:

http://www.diynot.com/forums/viewtopic.php?t=6026

Pictures help too.

 

[bucherdi]

It's a Eurostar oil boiler. We've lived here four years and I'm sure it only started happening recently. I'd have noticed the boiler running all the time. The only thing to change recently is a radiator got removed and a new one added.
Thanks
Dave

 

[Softus]

If your system was correctly installed, then either you have a frost stat that's operating at the wrong temperature or your programmer is faulty, because your system shouldn't be able to run with both CH and DHW deselected.

If you believe everything except the MZV to be working correctly, then you have a faulty/stuck MZV.

It's impossible to offer anything else without the information that, as I've pointed out, you're asked to provide at the outset, or pictures.

 

[bucherdi]

Sorry, is there something I've not provided? I've changed the programmer. What's an MZV?

 

[Softus]

Reality check 1:

The only thing to change recently is a radiator got removed and a new one added.

I've changed the programmer.

_______________________

Reality check 2:

You can get more advice here of course, but you'll need to supply all the information requested here:

http://www.diynot.com/forums/viewtopic.php?t=6026

Pictures help too.

Sorry, is there something I've not provided?

_________________________

What's an MZV?

MZV == Motorised Zone Valve.

 

[bucherdi]

do you sit and trawl these sites so you can make smart arse comments and generally p1ss everyone off? If you can't be bothered to be civil and assist in a normal human way, go an replumb your MZV you berk!

 

[D_Hailsham]

I am sorry you have had to endure the comments of soft*rs*; you are not the only one who is anoyed by his childish attitude. Put him in your ignore list!

Now as for your problem.

You say that you have been in the house four year and the problem has only started recently.

Was the problem there before you changed the programmer or has it happened after you changed the programmer?

What make/model was your old programmer?

What make/model is the new programmer?

What make/model is the motorized valve (the device with the actuator)?

 

[bucherdi]

Hi, thank you! I'm calm now.

Ok, I changed the programmer because I though that might be causing the problem. The old programmer battery had run out and in my ignorance thought it may be related. New and old are both Drayton Lifestyle LP522. The new one is a newer model but Avensys told me they're all backward compatible and I used the old backplate and did nothing with any wiring. That all seems to be fine. I assume the MZV is the thing I've been describing (the valve actuator) with the switch on the top of it that corrects the problem when moved. It's a Drayton 6W, ZA6, if that means anything to you?
Thanks
Dave

 

[D_Hailsham]

ZA6 means that it is a 28mm two port zone valve, which looks something like this:

Is this what you have?

28mm valves are usually used in gravity circulation hot water systems.

See Honeywell C Plan for more info.

In this installation the central heating is pumped but the Hot Water depends on the change in density of the water (hot water is less dense than cold, so it will rise up the pipe) for circulation. The zone valve opens and closes the circuit through the HW cylinder depending on the temperature of the water in the cylinder as measured by a thermostat about one third up the side of the cylinder.

One problem with this system (there are others!) is that the motor in the valve gives up the ghost and the valve gets stuck. You will see from the wiring diagram at the URL above that the grey wire is connected straight to the mains. If the switch in the valve is stuck over to the left (grey wire connected to orange) the boiler will run continuously. Thermostats and time switches will have no effect. An easy way to check is to disconnect the grey wire and see what happens. The boiler should run when you turn the wall stat up but the cylinder stat should have no effect.

If this is the cause, you have two options: replace the whole actuator (just the box on top of the valve; or, replace the synchron motor inside the actuator. (Older versions of the Drayton valve had unchangeable actuators, you had to replace the complete valve!)

 

[bucherdi]

Best I take some pictures (softlad will be pleased!). I have what is pictured as well, but that's not what I'm referring to. Your picture shows another box I also have, squareish, silver and shiny, also with a switch on it and made by honeywell but I'm not touching it. The other box that says 'valve actuator' on it is made by Drayton and says ZA6 on it. It's when I move the switch on THAT the problem goes away. I'll snap and post later.
Thanks for your help - it really is appreciated.
Dave

 

[Softus]

Ok, I changed the programmer because I though that might be causing the problem. The old programmer battery had run out and in my ignorance thought it may be related. New and old are both Drayton Lifestyle LP522. The new one is a newer model but Avensys told me they're all backward compatible and I used the old backplate and did nothing with any wiring. That all seems to be fine. I assume the MZV is the thing I've been describing (the valve actuator) with the switch on the top of it that corrects the problem when moved. It's a Drayton 6W, ZA6

That information is along the right lines; well done - you're learning. Now all we need is the rest of it.

 

[D_Hailsham]

I have what is pictured as well, but that's not what I'm referring to. Your picture shows another box I also have, squareish, silver and shiny, also with a switch on it and made by honeywell but I'm not touching it. The other box that says 'valve actuator' on it is made by Drayton and says ZA6 on it. It's when I move the switch on THAT the problem goes away. I'll snap and post later.
Thanks for your help - it really is appreciated.
Dave

So you have two boxes, one a Honeywell (model no?) the other a Drayton ZA6. Are both boxes attached to the pipe work? They should be! If so, they are both actuators and that changes things as you now have an S-plan not a C plan.

The picture I posted was just a general representation of a 2-port motorized valve. You can see the Drayton ones Here
From what you say, yours should be like the one on the right of the picture.

 

[Softus]

Before you ask a question please read this

 

[bucherdi]

Hi, both are attached to the pipework. The Honeywell has a number stamped on it of 272848. The picture you have is of the other, the Drayton, is exactly the one I have. The problem seems to be very intermittent. The pump was on all last night, as would have been the boiler had I turned the thermostat up, but corrected now, presumably as the programs kick in?
Sorry, I don't think I can add the snaps I've taken !