Heating on when everything is off!

[Statto]

I'm after some guidance please. I'm not DIY capable, and will almsot certainly have to "get a man in" if indeed I have a problem.
The scenario is this - a problem that has arisen in the last month or so..(been in the house almost 3 years)

I have a Drayton Tempus 7 CH & Water programmer which is set to switch both CH & water off at 10pm at night - which as far as I can see it's doing.

However, recently (but not every night) we wake in the middle of the night, the pump in the airing cupboard is going, the upstairs rads are hot, the downstairs ones are cold, the programmer is showing OFF for both CH & water and tweaking the central thermostat makes no difference - can't shut it down. The pump seems to run for a couple of hours then switches off.

How can it be on when it's off?
And why do only the upstairs rads come on?

I've no idea whatsort of system we have - there's a tank in the airing cupboard and a red and a white tank above that.

Any thoughts gratefully received..

Thanks

Statto

 

[bengasman]

I'm after some guidance please. I'm not DIY capable, and will almsot certainly have to "get a man in" if indeed I have a problem.

I have a Drayton Tempus 7 CH & Water programmer which is set to switch both CH & water off at 10pm at night - which as far as I can see it's doing.

However, recently (but not every night) we wake in the middle of the night, the pump in the airing cupboard is going, the upstairs rads are hot, the downstairs ones are cold, the programmer is showing OFF for both CH & water.
The pump seems to run for a couple of hours then switches off.

you do have a problem

 

[corgiman]

what boiler do you have and where is it located?

 

[Statto]

what boiler do you have and where is it located?

Thanks..

The boiler is an "Ideal Classic". I think the model number is FF260. It's located downstairs in the utility room that comes of the kitchen. The tempus Programmer is in the kitchen, the thermostat is in the hall.

The pump in the airing cupboard is a Grundfos Alpha.

Statto

 

[Technoplus]

your system may be a S plan type of system, In which I mean you would have motorised zone valves to control upstairs/downstairs and hot water.
As these valves control your pump and boiler directly and have a microswitch fitted inside them, which is fed from a wire that if wired correctly, by-passes your time clock.
If one of these microswitch contacts stick then this would keep the boiler on.
Alternativley there is a manual over ride on the side of the valve ( a lever that you can push to lock the valve open in the event of a failure) This may by mistake have been pushed into the lock positon while the valve was open thus keeping the boiler on even when the clock is off.

Good luck

 

[Technoplus]

You may also have a frost stat that is set wrong this would have the same effect

 

[Statto]

Thanks Technoplus

Had another butchers in the airing cupboard - there is a small grey box in there which says its a zone valve actuator, so I guess I do have zone control - though I didn't know that until now, and still don't know what it really means in practical terms.

There's a moving switch on the top of it that seems to move when the thermostat's turned up to fire up the heating. There's also what seems to be a small square push button on one side and an up/down switch on the other side of it (though it's so far in the airing cupboard I can't get my head around it to see what the markings against the switch say! Would either of those be the over-ride?

PS - it's a Drayton ZA6 unit and the slide switch is currently set to position "A" (the options are position "A" or "B"

If my heating comes on upstairs again when everything else appears off, is it worth flicking one or other of those switches to see if it turns off or will that b*gg*r it up!!!!



Statto

 

[D_Hailsham]

Had another butchers in the airing cupboard - there is a small grey box in there which says its a zone valve actuator, ... it's a Drayton ZA6 unit and the slide switch is currently set to position "A" (the options are position "A" or "B"

ZA6 Actuators are only used on 28mm valves, which are only found in gravity (no pump) systems.

If the valve has three pipes, it is not a zone valve but a mid position valve and the wrong actuator has been fitted.

How many pipes connected to the valve and where do the pipes go?

There's a moving switch on the top of it that seems to move when the thermostat's turned up to fire up the heating.

There's also what seems to be a small square push button on one side and an up/down switch on the other side of it (though it's so far in the airing cupboard I can't get my head around it to see what the markings against the switch say! Would either of those be the over-ride?

These are just releases so you can remove the actuator (the box part) from the rest of the valve if it needs replacing

If my heating comes on upstairs again when everything else appears off, is it worth flicking one or other of those switches to see if it turns off

All this will do is to remove the actuator. Leave alone


You mention a tank in the airing cupboard.

Is this a closed cylinder enclosed in a foam jacket?

If so, it's the hot water cylinder. Does it have a thermostat about one-third up the side held in place by a strap?

 

[Statto]

Blimey - this is getting complicated (for me)... bear with me....

There appears to be just one pipe on which the valve sits. It goes upwards where there's a small bare metal box with "Honeywell" stamped on it with a switch lever on the bottom of it, and the pipe then appears to branch over the top of the tank (presumably it goes into it - but I can't tell for sure.

Downwards the pipe disappears through the base of the airing cupboard.

The tank is bare - not jacketed - and says it's a Santon Premiere hot water heating system model TP210B.

I can't see anything on it that looks like a thermostat.

On a general note the house is about 7 years old - we've been here 3 years and the previous owner had it from new and made no alterations to the original installation.

Thanks again

(I'm learning loads here)!

Statto

 

[D_Hailsham]

The tank is bare - not jacketed - and says it's a Santon Premiere hot water heating system model TP210B.

OK. You have an unvented mains pressure water heater. There is info on the Santon here

There is a good explanation of this type of water system here

I can't see anything on it that looks like a thermostat.

You won't on this system

It sounds as if you may have a problem with the Santon cylinder.

This type of system needs specialist help as not all heating engineers are familiar with them. I suggest you contact Santon and ask for the name of an engineer.

Contact details are below:

Customer service/Technical
Tel: 0870 1600126
Fax: 0870 1600181
E-mail: [email protected]
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[Statto]

Thanks very much for the info and advice.

strangely it's been fine for a couple of nights now, but I think whatever else we need a maintenance check. Will contact Santon.

Cheers

Statto