Thermostat clicking

[cdbe]

My stat clicks, when around 20, not the usual but tick tock like a clock. I only noticed when I heard the boiler doing similar. It's about 5 years old, I've given it a dust inside so should I just replace it now - I presume whatever does the hysterisis has failed?
Thanks.

 

[DiyNutJob]

I have a gut feeling thermistors are below par. So, I was very happy to go thermocouple. I literally jumped on it when I found one.

 

[Deleted member 267285]

Can either @BlueLoo or @DiyNutJob provide a link to said wireless plug and play control? I’d love to see one, and recommend them to my boss.

 

[bernardgreen]

Search youtube. I am definitely not mistaken thermocouples are bimetal.

Comprehensive information about thermocouples https://www.tc.co.uk/thermocouples/thermocouples.html

 

[Harry Bloomfield]

Not quite. Mine is thermocouple based and I love it.

Thermocouple based, why would they use a thermocouple in a thermostat?

To try answer the OP's question...

Hysteresis is designed into on/off controls deliberately, or your boiler would be turned on and off too frequently. Electromechanical thermostats, due to their design, have rather too much hysteresis than is desirable, so they include a heater to attempt to reduce the hysteresis. When the stat switches on, so does the little heater, the heat from that, combined with the rising room temperature, then turn the stat off. The built in heater, is why they need a neutral.

The electromechanical stats, providing they are suitably located, have the advantage of not needing batteries replacing. If the location is less than optimal, then a wireless version might be worth having. The hysteresis in a wireless stat is programmed in, though some I hear, can be adjusted.

Hysteresis so far as stats are concerned, is the slight, essential difference in temperature between the switching on and the switching off points.

 

[BlueLoo]

See below

I'm confused.

The OP has a old fashioned bimetallic (i think) rotary room stat powered by 240v (probably).

Replacing the stat for a receiver and wireless head unti is as simple as it comes isn't it?

I did this with my house 15 years ago and installed a Sunvic device.

For upstairs, i switched the rotary ****e for a Sunvic digital stat.

Why is this controversial?

What am i missing?

 

[Deleted member 267285]

The point is no new wires. You plug the old wires in, and play!

That doesn’t make it wireless

 

[Deleted member 267285]

What am i missing?

How many wires does op’s stat have?

controversial, because people are making it.

 

[Deleted member 267285]

Dunno. I can't see behind the stat.
The instructions to it say its a powered switch so likely 3. Could be 5 but would still be a straight swap.

Exactly, we done know how many wires have been used, could be 2, which wouldn’t work for wireless. Could be 24v, we don’t know, this is why it’s getting confusing. Until we know all the relevant information, we can’t or shouldn’t be recommending this or that be done.

 

[Deleted member 267285]

If you don't know, then how did you come to the conclusion it won't work? I am a natural optimist, I always think things will work.

I haven’t come to the conclusion it wouldn’t work. I’m still waiting for this link, or does one not exist?

 

[DiyNutJob]

..

 

[cdbe]

Sorry, just got back from mum's house, boiling header tank but that's for another thread!

I don't know what I've missed but heres a photo of the inside, I have a box full of new ones in the garage so I'll swap it tomorrow. Not really bothered about a wireless one unless there's any advantage.

 

[MJN]

My stat clicks, when around 20, not the usual but tick tock like a clock. I only noticed when I heard the boiler doing similar. It's about 5 years old, I've given it a dust inside so should I just replace it now - I presume whatever does the hysterisis has failed?
Thanks.

Probably more likely to be a dodgy relay in an electronic stat like that.

As you've got a box full I wouldn't give it a second thought - just swap a new one in!

 

[ezkil]

Hello. I think you should thermocouple sensor beside thermostat. although , you sholud know temperature range in your environment.