Horstmann ChannelPlus H37XL

[JezzerH99]

I think I'm having problems with my ChannelPlus timer. Suddenly stopped working with a buzzing noise and now I notice I only get a relay click when I switch on/off one of the three circuits - the other two just cause the unit to buzz.

Would the best course of action be to try replacing the unit (as it seems like one or more of the relays might have gone or could there be some other cause?

Thanks.

 

[SixColdFeet]

For what it's worth, the same happened to me. Lights came on in the display for the ChannelPlus and buzzing sound from the controller box. Boiler would not fire and pumps not working.

Replaced the control box with the same but a newer version (Horstmann Channelplus XL37 V2). The baseplate is exactly the same so you just clip the old one off and clip the new one on.

I suspect the internal battery had died, or a component had just worn out and the relays had stopped working. A new controller box is about £110 and it is a simple fix you can do yourself.

 

[tony1tf]

I have just fixed a problem with my H37 programmer. The LEDs would light, but it wasn't pulling in the relays, so I suspected a low supply voltage. I measured 42 volts across the smoothing capacitor, but also checked with a battery oscilloscope (live mains connected so be careful!). I saw a large AC signal, so the capacitor wasn't doing its job - 22uF 160V. Replacing it got everything working again, and very little ripple. There was also still voltage across the Lithium battery, so it remembers the settings. These programmers still cost £120 so definitely a good fix.