Blue switchmaster 3 port to honeywell 3 port

[gooner49]

Got a faulty switchmaster 3 port (big blue haed type) so replacing with honeywell, the old had 6 wires where new one only 5, in booklet it says it wont work if programmer has not got hw off which it hasnt as it a big old clock type, i ahve read on here about linking over the old red and orange, now would this be all i need to do or would programmer also need changing? any help much appreciated

 

[twgas]

a new prog with a hot water off would be better, but not essential.
you do need to link the orange and red, and connect them to the new orange. the old white goes to the new grey, old yellow to new white. blue to blue and green to green.

 

[gooner49]

Cheers mate, and would that still work ch and hw independently?

 

[D_Hailsham]

in booklet it says it wont work if programmer has not got hw off which it hasnt as it a big old clock type,

But the old Switchmaster would not work if there was no HW OFF on the timer!

What is the make/model of your timer?

 

[gooner49]

not too sure mate, think its an old randall, big round clock in middle with two switches on right

 

[D_Hailsham]

not too sure mate, think its an old randall, big round clock in middle with two switches on right

Can you post a pic of the timer?

With a Honeywell 3-port valve, if you do not have a HW OFF terminal, you will only get CH ONLY if the HW is up to temperature. Otherwise you will get CH and HW. This assumes that the HW stat on the side of the cylinder has all three terminals wired up.

A new timer will get over this. You need one with two channels, e.g Drayton LP programmer, not LP timer. There are four to choose from.

 

[gooner49]

worked a treat lads, thanks

 

[Ollie9]

Hello team,

I have also had problems with this set-up. I changed from an old switchmaster in the summer, everything seemed ok but I was only demanding hot water....until last weekend when I tried to put my heating on!

I have just been through the wiring (including the colour changes for the new Honeywell) and found that I did not have any wiring to the HW Off at my timer (Sunvic 207xl) so I have inserted a single wire from the H/W off terminal to the grey wire on the 3 way which also links to the cyl stat.

Now the boiler keeps stopping, so I have turned it to its maximum, and it has fired-up. Do you think that my stats are blown? The cycl stat dous not 'click' in any position.

Please help as I have no heating!!

Thanks!

 

[twgas]

What demands do you have when the boiler stops?