Fitted a wireless stat

[haza1]

Hi all

I have fitted a wireless room stat (as it has never had a stat) to the existing system (on or off via timer) gate valve for water or heating

But when timer is on the stat wont work ie control temp, but by just turning stat up it works as it should

On the stat and the timer have the supply + 3 connections ie 1com 2off 3on what do i have to link so i can control the temp when using the timer

Regards

 

[Dan Robinson]

You need motorised valves for a start.

 

[haza1]

Thanks for quick responce Dan

But sorry for been a bit wet behind the ears but doesn't a motor valve just turn your system to water or heating or both?

All im looking for is to control heating temp when using a timer

Regards

 

[Dan Robinson]

Yes, but the motorised valve is what the thermostat turns off. Which in turn shuts off the heating. Gate valves are not motorised.

I suppose you could rig you stat up to a buzzer. When the temperature is reached. It buzzes, then you can get up and turn off the gate valve

 

[haza1]

LOL

But its working without a motorised valve at mo ie heating or water

All i want to do is controll boiler when heating is on to be able to use timer when it gets to temp shut boiler down

 

[Dan Robinson]

Dude, seriously?

 

[ChrisOxford]

Like Dan, I'm confused!

Please tell us:

(1) What kind of heating system do you have? A combi, or a conventional system with a separate tank, pump and so on?

(2) If the latter, does it just have a timer/programmer and pump, and no other electrical bits (other than the boiler itself)? Specifically, can you confirm it has NO motorised valves?

(3) And why did you mention gate valves? You are talking about red-handled "taps", aren't you?

C.

 

[haza1]

Thanks Chris.
Yes it is a conventional system
With a pump and a timer and no room stat with no motorised valves the gate valve is just for water or heating and yes it has a red handle

I want to control temp when using the timer, at the mo both of them work but not at the same time ie if timer is turned on the stat has no control over the temp

Regards

 

[ChrisOxford]

Thanks for the info.

...the gate valve is just for water or heating and yes it has a red handle

Still not sure what you mean by "for water or heating". You shouldn't have to touch gate valves unless you're doing maintenance on the system. Tell us more!

...if timer is turned on the stat has no control over the temp

This sounds like a simple miswiring issue.

The thermostat's contacts should be wired IN SERIES with the live wire to the pump, so that it switches the pump off when the house gets up to temperature. The part of the timeswitch that controls the pump should be IN SERIES too. In other words:

Live mains from fuse -> timer -> stat -> pump -> neutral mains

OR

Live mains from fuse -> stat -> timer -> pump -> neutral mains

From what you say, the stat contacts and the timer contacts are incorrectly wired in parallel with each other, so that when the timer comes on, the stat can't switch off the pump and so has no control over anything. If that's the case, you should also be able to switch the heating on using the thermostat even though the timeswitch is set to off!

Your stat sounds like it has "changeover" contacts (as well as Live and Neutral supply). So you only need to use two of the contacts, COM and probably ON. If it behaves the wrong way round (i.e. heating goes off when house gets cold and vice versa), use COM and OFF instead.

C.

 

[haza1]

Thanks Chris

The gate valve shuts off the supply to the central heating when closed so only get hot water you may call it a summer valve!

As for the wiring i think it is a easy fix if you know how! i could try different wiring combinations and risk a few 3amp fuses but would like to do it the correct way

below are the two wiring diagrams

Untitled

• haza1
• 19 Oct 2011
• 1

THIS IS TIMER CONTROL

Untitled

• haza1
• 19 Oct 2011
• 1

THIS IS WIRLESS STAT

On the stat using connections L1 and LX and on the timer i think it was 1 and 3

Regards Shaun

 

[Whitespirit66]

...the gate valve is just for water or heating and yes it has a red handle

Still not sure what you mean by "for water or heating". You shouldn't have to touch gate valves unless you're doing maintenance on the system. Tell us more!

Chris

Think this system has gravity hw. Instead of having an anti gravity valve to stop the gravity hw circulation leaking into the rads when only hw is on, the op has a gate valve. HW on - just boiler with gv closed. Ch on - boiler + pump and open gv to let pumped flow through rads. From the days when you had a man to do it for you!

Ian

Edit - Suppose could be fully pumped, and the gv serves the purpose of a 2 port valve.

 

[ChrisOxford]

That's a massive help, Shaun.

Mmm, it sounds a bit different from any system I've seen.

Two more questions for you...

(1) As far as you understand it, did the timer switch both the heating AND the hot water on and off together, when that gate valve was open?

(2) And did the pump run even in the summer, when you wanted hot water only?

C.

 

[ChrisOxford]

Hi Ian (Whitespirit66),

Just seen your post, we must have been typing at the same time!

That makes perfect sense about the gate valve.

If it's really a gravity HW system with a gate valve to shut off the rads, what do you reckon the timeswitch did? Switch both the boiler and pump together?

A system I've worked on had pumped CH and gravity HW with no motorised valves, but had a 2 channel programmer. Selecting HW fired up the boiler alone, and selecting CH ran both the pump and the boiler.

Edit - Suppose could be fully pumped, and the gv serves the purpose of a 2 port valve.

That's what I was worried about, because Shaun seems to have a single-channel timeswitch, not a 2-channel programmer... would make life difficult for the OP unless he was willing to install a motorised valve somewhere. Maybe Dan has a crystal ball

 

[haza1]

Hi Chris

Yes to both questions

Regards shaun

 

[ChrisOxford]

Yes to both questions

So, sounds like fully pumped system then. Ian's second thoughts were right.

You could install your wireless stat so that it switched off the boiler and pump when the house got up to temperature - not difficult at all. The downside would be that your hot water would stop being heated when the house had warmed up, which could well mean that you end up with less hot water than you need, especially in the spring and autumn when you only need a little bit of central heating.

Do you want to give that a go? Nothing to lose really, I suppose? Happy to draw you a wiring diagram if so.

What do the experts think?