pcb?

http://www.torreelectrics.co.uk/acatalog/Dimplex_electric_fire_Obisidan_OBS20_Series_A.html

It may be your fire or not. You didn't say the type. The diagram shows the location of the PCB (Item 15).

For someone who does not know what they are doing, the simplest expedient is to either 1) Ask someone who is competent to look or 2) Test by substitution.

One brief other thought: I believe these controls are infra-red, as opposed to radio. If that is the case, you can test your handset is issuing commands by simply viewing it thru the viewfinder of a digital camera (Camera or phone camera) and operating the remote. If the remote is working you should see the infra red emitter at the end of the remote, lighting up. Try it with a known good remote - say - your TV remote and you'll get the idea.

belp
November 2016

A few moments research found this...

Dimplex Rectory fan heater the coal effect will not turn off either with the remote control or with the switch on the unit

The previous question in the Fan Heater category

And this original answer...
It could be the PCB they cost about £60 only testing will prove it

The PCB will be inside the fan heater
Testing it will require test equipment and confidence

Good Luck...
November 2016

OK. You tell us what the item is, in which you believe there is a PCB and we may be able to do the same Google search you could have and find out a little more info.

Until we know what it is (Make, model, brief description) and given the fact that we aren't psychic, we can't help much

belp
November 2016