New Honeywell Sundial RF2 Pack 2 ST9420C fitted! help!

[russt93]

Hi,
I've just replaced at Danfloss RANDALL 102 Analogue with a Honeywell Sundial RF2 Pack 2. I thought it would be simple enough to swap the two.

I've seen another message on this forum changing the same Randall for the same ST9420C. On this forum message the guy said you just need to do the following: -

RANDALL------------------------------Honeywell RF2
6------------------------------------------L
5------------------------------------------N
1------------------------------------------3
2------------------------------------------4

This seems correct to me too, the above for the Randall are labelled the same on itself (L, N and Heating, Water), the only thing exact was a "com" which was wired from live. The ST9420C has the same in their PDF here as suggested above: -

www.uk-plumbing.com/brochure/honeywell/Pack2Brochure.pdf

The hot water works fine, the heating however will only come on when I also turn the heating on. The heating on its own will not kick in the boiler.

Have I missed something?! Any help is much appreciated!!

 

[RF Lighting]

There's often some DIP switches or jumper contacts on the back of the programmer. Have you set these correctly for the type of heating system you have?

 

[russt93]

Nope, no dip switches on the back of it.

 

[Dan Robinson]

S-PLan?
Y-Plan?
W-Plan?
C-Plan?

What have you?

Have you checked 230V is coming off the heating call from the timer?

 

[RF Lighting]

It says in the PDF you linked to

"Installer mode - allows control to be matched to the system"

So I'm guessing you need to go into installer mode and match the controller to your type of system.

It should tell you this in the instructions that came with it.

 

[Dan Robinson]

Not for this kind of problem it doesn't.

 

[matt1e]

The hot water works fine, the heating however will only come on when I also turn the heating on. The heating on its own will not kick in the boiler.

Have I missed something?! Any help is much appreciated!!

It likely doesn't work because you have gravity hotwater and pumped central heating, you will either need to upgrade to one of the Plans Dan has mentioned or fit a different controller as its not compatible the way your system is

Or are you saying that you used to have the ability to select CH only?
because you can't with a 102

Matt