Central heating programmable thermostat: changed system same problem !!

[Bobba]

In October last year I sought opinion on a problem with a Salus system. The problem was that when on the evening setting, 4-9 pm, somewhere between 7-8 pm (I didn’t sit and watch it) the ambient temperature reading with a mind of it’s own switched to 20.5 degrees. This overrode the programmed setting temperature so the central heating shut down.  

lots of friendly suggestion but no definitive solution. My friendly heating engineer couldn’t solve it either.

Well, to resolve the problem, earlier this year I replaced the Salus with  a Drayton Digistat +3RF. I didn’t need the CH during the summer months but used it earlier this week and ****** me the problem continues. Quite unbelievable. 

It was suggested last time that something in the property may be interfering, but we have nothing that regularly trips at that time. Could it be an external source? My brain is addled on this one so any thoughts gratefully received. Thanks.

 

[B725]

I assume you have a Y plan or S plan heating system are you sure the mico switch on the motorized valve is not stuck therefore giving your controls a false reading?

[old man]

Sounds like Alexa is upset to me?

[ph5172]

Can you not just set an extra timed setting to bring it back on again adjusting the on off time forward by 15 mins to give you a rough time of the event. 
 

do you have a cctv system or outside lights 

[JohnfromUK]

Just a suggestion.  IF it is caused by external interference - which could be either something in your property, or something else locally, it is likely it will occur at the same time daily.  Digistat 3 is a 433 MHz RF device, and I'm not sure what else could interfere with that, but it is a very popular band for (quote follows) "433MHz is a commonly used frequency band for all types of equipment that require little power, such as garage door openers, headphones, baby phones and remote controls. Also many inexpensive transmitters and receivers for switching devices and light dimmers operate on the 433MHz band."

[Bobba]

Thanks one and all

2 hours ago, JohnfromUK said:

Just a suggestion.  IF it is caused by external interference - which could be either something in your property, or something else locally, it is likely it will occur at the same time daily.  Digistat 3 is a 433 MHz RF device, and I'm not sure what else could interfere with that, but it is a very popular band for (quote follows) "433MHz is a commonly used frequency band for all types of equipment that require little power, such as garage door openers, headphones, baby phones and remote controls. Also many inexpensive transmitters and receivers for switching devices and light dimmers operate on the 433MHz band."

our next door neighbour has a security system (upgraded) so will monitor against CH thermostat times

16 hours ago, ph5172 said:

Can you not just set an extra timed setting to bring it back on again adjusting the on off time forward by 15 mins to give you a rough time of the event. 
 

do you have a cctv system or outside lights 

I like the workaround solution of timer settings. Thanks.
No, we do not have cctv or lights but neighbour does!

18 hours ago, B725 said:

I assume you have a Y plan or S plan heating system are you sure the mico switch on the motorized valve is not stuck therefore giving your controls a false reading?

will ask our CH chap to check