replace old drayton combi stat with digital

[chatlow]

We have an old combi stat in the hall way which we would like to replace. Doesn't seem too accurate plus would like a digital stat until we replace the system.
Is this possible? Is it a DIY job for a relatively competent DIY'er? We have an old ideal classic boiler with a heat store cylinder in the airing cupboard, no water tank

Thanks,

 

[BlueLoo]

If you can wire a plug, i don't see why not.

 

[chatlow]

that's what I was hoping to hear. also to check if analog thermostats can be swapped out with digital, i.e compatibility

 

[stem]

Much will depend upon the wires that presently go to the existing room thermostat and the wires that are required by the new one.

Some mechanical dial thermostats sometimes only have two wires connected, that operate simply as a switch to turn the heating 'on' and 'off', but some of the newer thermostats as well as the switch, also require 230V to provide them with operating power too. which may, or may not be present.

This is where it gets tricky, because the Drayton Combi-Stat ideally should have 3 wires, but sometimes doesn't as the following diagrams show:

In the first example you will see that there is a wire connected to the top N terminal, but in the second there isn't. So, If there are only two wires currently being used with yours (i.e. there isn't a neutral) a battery operated thermostat might be a better option as it doesn't need the 230V supply.

EDIT:

check if analogue thermostats can be swapped out with digital, i.e compatibility

The terms analogue & digital refers to the way the thermostats function internally, but at the end of the day both contain a simple on/off switch that actually controls the heating. So, from an electrical point of view, both are identical. There are exceptions that only work with certain boilers and that carry data signals, but for standard room thermostats it won't be an issue.

 

[chatlow]

ah thats very good to know, thanks!
We would prob be looking to get nest or hive with the new system next year but wondering if we could buy it now and use on the existing system ( i know zones won;t be possible yet) but will check the wiring of this thermostat first

 

[stem]

Both Nest and Hive have remote thermostats. Hive and Nest-e are battery powered, but Nest 3rd Gen requires a 12v supply from its receiver or a separate plug in power supply.

You will notice I mention the term 'receiver' which can complicate matters. Both Nest and Hive have a receiver that connects to the existing wiring and both receivers do require a 230V supply for operating power. The other problem is that most people don't want the receiver mounting on the wall where the existing thermostat is located, and if it's mounted elsewhere, this would involve re-routing the existing thermostat wiring to the new chosen receiver location.

For DIY, the easiest way is to buy a new room thermostat that doesn't need a receiver, aka a 'wired' thermostat (as opposed to 'wireless' thermostat) and just swap them over.

 

[BlueLoo]

that's what I was hoping to hear. also to check if analog thermostats can be swapped out with digital, i.e compatibility

Whats the old one?

 

[chatlow]

Whats the old one?

Drayton Combi stat

 

[chatlow]

Both Nest and Hive have remote thermostats. Hive and Nest-e are battery powered, but Nest 3rd Gen requires a 12v supply from its receiver or a separate plug in power supply.

You will notice I mention the term 'receiver' which can complicate matters. Both Nest and Hive have a receiver that connects to the existing wiring and both receivers do require a 230V supply for operating power. The other problem is that most people don't want the receiver mounting on the wall where the existing thermostat is located, and if it's mounted elsewhere, this would involve re-routing the existing thermostat wiring to the new chosen receiver location.

For DIY, the easiest way is to buy a new room thermostat that doesn't need a receiver, aka a 'wired' thermostat (as opposed to 'wireless' thermostat) and just swap them over.

will have a think then and see how the wiring looks to the old stat. May just replace with a cheaper digital one for now if Hive/Nest over complicate things or need additional configs done

 

[BlueLoo]

will have a think then and see how the wiring looks to the old stat. May just replace with a cheaper digital one for now if Hive/Nest over complicate things or need additional configs done

Personally, i wouldn't bother with low level heating controls that just supplant the old stats.

They are expensive and not much better than what's in.

Switch it out for a digital stat (cheap as chips) and then do a bit of research and look to upgrade to a fully controlled heating system.

Gas ain't cheap anymore.
The old days of heating whole floors and running around manually adjusting trvs should be put in the history bin.

 

[chatlow]

Personally, i wouldn't bother with low level heating controls that just supplant the old stats.

They are expensive and not much better than what's in.

Switch it out for a digital stat (cheap as chips) and then do a bit of research and look to upgrade to a fully controlled heating system.

Gas ain't cheap anymore.
The old days of heating whole floors and running around manually adjusting trvs should be put in the history bin.

thanks. any recommendations on a digital stat that would be a direct swap out with my current one? I'll confirm the wiring later, assuming it's easy enough to open the unit

 

[stem]

Tado is a decent product. They make a smart thermostat that can be wired and only requires a two wire connection. You can see details of it here.

 

[chatlow]

decided I will just replace analog with a basic (more reliable) digital stat, nothing too fancy, and a like for like rather than messing with the heating controls next to the boiler.
Are there any recommendations for a decent budget digital stat?

 

[CBW]

Loads available, Siemens, Esi, EPH, heatmser, Honeywell to name but a few.