Switchmaster 900 Instruction Manual Required

[narcosis]

Does anyone have an instruction manual for a switchmaster 900 central heating/hotwater controller that they would not mind sharing?

I have read other similar posts and I can work out the controls but an instruction manual is always useful and this is really what I am after.

One problem I do have is that there is no arrow to line up the timer dial!!

How easy is it to replace the old controller with a new one?

Thanks in advance.

Neil

 

[JohnD]

It is a brand used by Drayton (part of Invensys)

You will probably have to use their "contact us" link as I can't see it online

http://www.draytoncontrols.co.uk/content.aspx?id=1579

It is very easy to change for another programmer. They have a "Programmer Compatibility Guide" page 50 of their 2009 catalogue which you can download

IIRC is is very similar to the SM2 programmer which is very easy to use and intuitive even for the older untrained user.

 

[seco services]

You set the time by rotating the main dial clockwise so the correct time is against the mark near the Advance knob.

The four coloured markers are ON, OFF, ON OFF. You can move the markers by pulling them out (away from the centre) sliding them round the dial then pushing in again. This allows you to have two periods when the heating/ hot water are on. (You will have to experiment to find out what each marker does but the will always be in the order: On, Off, On, Off.)

The slide switches allow you to override the marker settings:

Constant means the heating/hot water is on 24 hours a day

Once that is goes on at the first marker and off at the last, i.e ignores the two intermediate markers.

Twice means it goes on at the first marker, off at the second, on at the third and off at the fourth.

Off means it is off all the time.

The advance knob allows you to temporarily override the setting. So, if the heating/ hot water has just gone off and you want to bring it back on again, e.g for a late night party, you just turn the advance knob anticlockwise until it clicks and the boiler will come on. It will then stay on until the next schedule ON time. You can turn it off again by turning the knob anticlockwise until it clicks.

Similarly, if the boiler is ON and you want to turn it OFF, e.g going out for the day, you can turn the knob clockwise which will turn the boiler off and stay off until the next scheduled ON time.

 

[narcosis]

Thanks chaps,

I will check out the links, thanks.

I guessed the basis of the on-off on-off and as you say a bit of trial and error is in order but it is always good to have the manual especially if you have to sell the house on etc etc. Currently it appears that I cannot run the central heating without having the hot water on as well, as the switches are linked. The only time they are not linked is if you leave the hot water on (constant, twice or single) and the central heating off. I have read in the installation manual (I have that!) that you can adjust the programmer to seperate the two but I am uncertain if that means that I can have the central heating on without the hot water, would this be a functionality I can expect out of this type of older controller?

Kind regards,

Neil

 

[JohnD]

depends if you have fully pumped system, or gravity HW

Post some pictures of the pipes around the boiler, pump, cylinder and valves if unsure.

Is there a thermostat on the cylinder?

 

[narcosis]

good question, I will check this evening. There is a central heating expension tank in the loft and a cold water tank that feeds the hot water tank.

cheers
Neil

 

[narcosis]

Thank you for that link, I asked for a copy of the manual and one was sent the same day, I will post up pics soon so that others can have a copy if they ever need it.

I also took some pics of the system last night to be posted soon.

I adjusted the programmer last night to de-link the central heating and hot water slider switches but nothing happened when I tried to run the central heating on its own so I guess the system is not set-up for this arrangement. Can someone please explain why the central heating requires the hot water to be hot prior to working. I ask because my new house appears to have the same system as my current house and that system allows independent use of heating and hot water.

Kind regards,

Neil

 

[JohnD]

Can someone please explain why the central heating requires the hot water to be hot prior to working.

depends if you have fully pumped system, or gravity HW

Post some pictures of the pipes around the boiler, pump, cylinder and valves if unsure.

Is there a thermostat on the cylinder?

 

[narcosis]

Apologies for the delay, here you go:

and the switchmaster manual:

Thanks

Neil

 

[JohnD]

you appear to have a fully-pumped system with a 3-port motorised valve.

Sometimes the valves leak internally with age, or just stop working.

Or perhaps yours has been set to hot-water priority or has been set to Gravity HW by mistake.

It does not need to be like that. But I would have thouight it would get the cylinder hot in half an hour or so, so no big deal.

 

[narcosis]

Thanks John,

You are right, it only takes 20-30 minutes to heat the tank so not too bad. I am beginning to think the controller was not wired for that operation. I have someone coming to service the boiler soon so will ask them to take a look then.

cheers and I hope someone else will find the instructions useful.

Neil

 

[narcosis]

John,

I noticed another problem yesterday. I ran the HW only but after heating the tank this then also ran the CH. So it appears that I have no control over the HW or CH other than to turn it in or off. Does this sound like a 3-port valve failure?

The plummer is coming Friday so I can chinwag with him about it then but I little bit of insight goes a long way!

cheers

Neil