Wireless Programmer Advice

[hightower]

My mates just been on, his combi boiler isn't working with the timer so he's asked me to install a separate unit.

First of all is this even possible, and second can anyone recommend a budget programmer that would do it. Think it would need to be wireless programmer unit with a receiver at the boiler. I was having a look at a Salus model for £35 but think they are single channel? I'd need 2 channels I think

 

[hightower]

Sorry, it's a combi boiler doh, so I'm right in thinking I only need a single channel (for the heating) as the hot water will come on automatically when water it called for by the tap?

 

[hightower]

This is the one I was thinking of getting to fit?

Salus Wireless Programmable Room Thermostat c/w Overide RT500ROF - Mr Central Heating - https://www.mrcentralheating.co.uk/salus-wireless-programmable-room-thermostat-c-w-overide-rt500rof?utm_source=google_shopping&gclid=CjwKEAiAg5_CBRDo4o6e4o3NtG0SJAB-IatYPQ0q0LFIHVLADHNmGcrMmRp7InQQczyEwXIQJOrd2BoC6Tbw_wcB#.WEgTTvmLSUk

 

[Uheat – Jake]

If you're looking for something slightly more expensive but two channel then I'd recommend the Heatmiser SlimlineRF Kit, simple to use is a tidy little unit.
Wireless Programmable Thermostat - Heatmiser PRT-W Kit - http://www.uheat.co.uk/wireless-programmable-thermostat-heatmiser-prt-w-kit/

 

[Sparkie30]

Sorry, it's a combi boiler doh, so I'm right in thinking I only need a single channel (for the heating) as the hot water will come on automatically when water it called for by the tap?

You only need a single channel bucause combis are instant water heaters.
Plumb center have their own brand and works perfect
Center Programmable Room Thermostat EHE0200361 | Plumb Center - http://www.plumbcenter.co.uk/product/center-radio-frequency-programmable-room-thermostat/

 

[hightower]

Will the boiler be capable of having it if the boiler is expecting it to use its own timer? Or is it just a case of setting boiler to permanently on and then dropping this in the current thermostat switching?

 

[Sparkie30]

Will the boiler be capable of having it if the boiler is expecting it to use its own timer? Or is it just a case of setting boiler to permanently on and then dropping this in the current thermostat switching?

Should be more than capable, you turn off timer on boiler set to 0.
Then a 4 or 5 (depends how you want to do it)core cable from reciver to boiler.

 

[Last plumber]

My mates just been on, his combi boiler isn't working with the timer so he's asked me to install a separate unit.

First of all is this even possible, and second can anyone recommend a budget programmer that would do it. Think it would need to be wireless programmer unit with a receiver at the boiler. I was having a look at a Salus model for £35 but think they are single channel? I'd need 2 channels I think

Sender unit switched live to switched live in boiler.

Make sure that your on the right terminal in the boiler.

For example, Vaillant have a 240V , 24V and ebus circuits and a lot of others have similar options.

Most combi boilers offer a supply for the circuit you choose too.
So your programmer is just a switch for that particular circuit.

Any RF programmer should work any boiler though, it doesn't need to be same make.

You are supposed to be gas safe registered to open boiler case though.

 

[hightower]

Thanks. Think I need to look into 230v and 24v contacts a bit and see what all that is about....

 

[Sparkie30]

You are supposed to be gas safe registered to open boiler case though.

Oh dear,
do you actually know anyone has been prosecuted just for opening the boiler case also can you help me find that exat law please?

Thanks

 

[Last plumber]

Oh dear,
do you actually know anyone has been prosecuted just for opening the boiler case also can you help me find that exat law please?

Thanks

No I Don't know anyone

 

[Leesparkykent]

What make is the boiler?

 

[hightower]

What make is the boiler?

Hi mate, I have no idea. I'll drop him a message to find out.

 

[hightower]

@Leesparkykent It's a Worcester green star 25si

 

[hightower]

So looking at manual I believe I need to take the Ls to the common of the receiver, and the Lr comes from the NO of the receiver to the Lr on the boiler. Would this be right?

 

[Last plumber]

So looking at manual I believe I need to take the Ls to the common of the receiver, and the Lr comes from the NO of the receiver to the Lr on the boiler. Would this be right?

Yes, that's right. It's 230V on those so you could use a 230V from a link in programmer. Either way. ( Double check it is 230v, I'm sure it is but not looked at a Worcester for a few week ).

 

[hightower]

Just trying to get my head around CH in general, so with this being 230v does that mean I don't need to take the feed from the boiler's Ls and Ns terminals, and can take it from a suitable feed, and then just provide it with a Lr at 230v?

I know this probably won't be practical, just trying to get my head around the theory.

 

[Last plumber]

Just trying to get my head around CH in general, so with this being 230v does that mean I don't need to take the feed from the boiler's Ls and Ns terminals, and can take it from a suitable feed, and then just provide it with a Lr at 230v?

I know this probably won't be practical, just trying to get my head around the theory.

Yes. Sometimes is easier depending on how many cores in flex/cable etc.
It's no prob if it's 230V .

 

[hightower]

Yes. Sometimes is easier depending on how many cores in flex/cable etc.
It's no prob if it's 230V .

So when and why is 24v or volt free contacts used, if you don't mind me asking?

 

[hightower]

So, I think by volt free that doesn't mean there's no voltage on the contacts, just that the voltage is separate from the mains voltage. So, a solenoid that is switched open and shut by the 230v mains, but the contacts on switch are separate and therefore can be any voltage you need? Am I thinking about this correctly?

Therefore, if the boiler takes 230v on the switch you can just link the 230v of the supply to the solenoid to the common, and that way it will send 230v up it when it is closed? However, if the device to be switched need a lower voltage, you instead apply that to the common terminal so that the correct voltage is returned when it is closed?

I think I'm slowly getting my head around this, it's the naming of "volt free" that threw me off.

Why would a boiler not want 230v on the switch, I mean, why would a boiler need a 24v return to switch it? Can you give me an example of a boiler that uses this so I can download the manual and take a look?

 

[Last plumber]

So, I think by volt free that doesn't mean there's no voltage on the contacts, just that the voltage is separate from the mains voltage. So, a solenoid that is switched open and shut by the 230v mains, but the contacts on switch are separate and therefore can be any voltage you need? Am I thinking about this correctly?

Therefore, if the boiler takes 230v on the switch you can just link the 230v of the supply to the solenoid to the common, and that way it will send 230v up it when it is closed? However, if the device to be switched need a lower voltage, you instead apply that to the common terminal so that the correct voltage is returned when it is closed?

I think I'm slowly getting my head around this, it's the naming of "volt free" that threw me off.

Why would a boiler not want 230v on the switch, I mean, why would a boiler need a 24v return to switch it? Can you give me an example of a boiler that uses this so I can download the manual and take a look?

https://www.google.co.uk/url?sa=t&r...47.pdf&usg=AFQjCNEEZPLuEg435Gdc-mejUBX16zKfbg

Have a look at Vaillant. All three ideas/methods are available with those.

There's 230V, 24V and ebus. ebus is specific to Vaillant.

As far as volt free goes, that is a funny thing to get your head around. I always think of it as a circuit that doesn't actually run anything by itself, directly.

In my case a volt free circuit normally includes a PCB. So the switching is done via components on that board like transistors, relays etc. Things like volt free switching on a room stat would just close a circuit for the board to recognise.

Some say that volt free is Free, as in Free like non specific.

 

[hightower]

Well I read one article that said volt free just means the relay contacts are separate (free) from the supply voltage. Then I read another article saying volt free means exactly that, there isn't a voltage sitting present but some circuit board wizardry is watching the cable for continuity - and when the switch is closed it picks up on the continuity and acts on it.

 

[hightower]

Thanks for that link, very helpful. Just looking through and on page 27 it says not to use 7,8,9 (20v) terminals in the UK.

 

[Last plumber]

Thanks for that link, very helpful. Just looking through and on page 27 it says not to use 7,8,9 (20v) terminals in the UK.

Wizardry ......Yep that's it.
another subject all together.

 

[Leesparkykent]

The controls should really be fed from the LS terminal within the boiler so they are protected by the internal fuse. This way its connected in accordance with the manufacturers instructions.

 

[Last plumber]

The controls should really be fed from the LS terminal within the boiler so they are protected by the internal fuse. This way its connected in accordance with the manufacturers instructions.

Not all MF's say that and the only thing that should be supplied via that particular circuit is the switching of it.
So in the case of a Programmer, you wouldn't run the L N supply to a programmer from the boiler and definitely not from that source, so you wouldn't be protecting the control itself with the internal fuse anyway !
The switch circuit ( in this case Lr Ls ) is to tell the board to fire the boiler. The boilers internal functions and components e.g. Pump, fan etc are powered via the permanent live supply.

 

[Leesparkykent]

Not all MF's say that and the only thing that should be supplied via that particular circuit is the switching of it.
So in the case of a Programmer, you wouldn't run the L N supply to a programmer from the boiler and definitely not from that source, so you wouldn't be protecting the control itself with the internal fuse anyway !
The switch circuit ( in this case Lr Ls ) is to tell the board to fire the boiler. The boilers internal functions and components e.g. Pump, fan etc are powered via the permanent live supply.

Hightower says its a worcster bosch 25si so yes the programmer should be fed from the LS/230V out terminal if you follow the manufacturers instructions/diagrams.

 

[Last plumber]

Hightower says its a worcster bosch 25si so yes the programmer should be fed from the LS/230V out terminal if you follow the manufacturers instructions/diagrams.

It does say that, you would however be running the Programmer via the board which I personally don't like the idea of for numerous reasons.
I prefer the programmer to take it's supply from the system wiring. If you ring Worcester tech, they'll tell you its a suggested way of doing it, not a must. It is a provision they make. There is more than one way to skin a cat. There is no harm in feeding a switched live to the boiler Lr.