Heatslave 12/14 no heat, in fact nothing at all.

[vick1]

Hi,
We have an oil fired worcester heatslave 12/14 with a built in timeclock. Since yeasterday we have had no heat or hot water. The thing won't even fire up when a hot tap is turned on, we have tried calling for heat/hot water on the timeclock both together and individually, the red lights light up but nowt happens. There is power to the boiler and timeclock but no pump spinning burner movement or infact any noise except for the hot water flow switch that clicks when a tap is turned on. I have looked for lock out buttons but none have tripped and the lock out light has not lit. PCB??? Time clock??? or could it be something completely different???

Any clues, I need a hot shower, getting a little whiffy around here

You help is greatly appreciated

 

[oilman]

There is a 3.15A fuse on the circuit board, and there is the possibility the diverter valve has failed.

 

[Agile]

As you say it clicks when you turn on a hot tap then the diverter valve must be working. Even if it had failed you would still get heating.

More likely the pump or something else has failed and blown the fuse or perhaps the fuse just died of old age.

Is there any manually reset over heat stat?

Tony

 

[oilman]

As you say it clicks when you turn on a hot tap then the diverter valve must be working. Even if it had failed you would still get heating.

Not necessarily, the contacts on the diverter valve may have burnt out, or the spindle may have gone stiff and is not allowing the contacts to operate correctly. It is a Honeywell 3-port valve.

The click from the flow switch depends only on whether water is flowing (or not).

 

[vick1]

The fuse looks ok (clear glass fuse and i can see the intact wire inside), there is also power to the integral plug in clock. There is water flowing from the hot tap although it is cold, and that is the click i hear, when the tap is turned on and again when it is turned off. I know about the manual/auto lever on the 3 port valve and have slid that to manual which sadly made no difference.

Please help, the smell is getting unbearable, i need a hot shower

 

[mikeyd]

I had one of those boilers and this once happened to me. Are you sure you found the overheat lockout?

From the user manual:

Your boiler is fitted with a manual reset overheat thermostat. If
the burner fails to operate and the LOCKOUT indicator light is not
illuminated, check the overheat thermostat by pressing the reset
button. The thermostat is located on the underside of the electrical
panel and is accessible by removing the boiler casing front panel. If
the problem continues after pressing the reset button, consult a
service engineer.

It is behind and just above the bottom of the panel with the controls on, and about half way between the 2 temperature knobs.

 

[Nixt]

Before you do this check there is adequate pressure - at least 0.5bar on the pressure gauge if not re-charge it.

 

[vick1]

It is behind and just above the bottom of the panel with the controls on, and about half way between the 2 temperature knobs.

Found that on the underside, it's a little red button, pressed with no difference to anything. also topped the pressure up by about 0.2 bar so it was at 1.0 bar again no difference. lights are still illuminated on the time clock and power to the board but nowt else happening.

Thanks for all the help and ideas so far guys

 

[cjb1971]

The cover on the pcb really needs to come off and the live from the clock needs tracing with a multimeter to find out where it is failing-u certain its not locked out and the lockout bulb has blown,therefor not showing the fault,u say you have looked for the lockout buttons-have u actually pressed the reset button on the burner??

 

[vick1]

Already pressed both resets, burner and the one under the control box, with no joy Is there anyway to bypass the timeclock, i've seen it's just a plug in type?

I've also checked there is oil coming through too. Pump doesn't run and burner is silent, not a dicky bird happening.

 

[oilman]

I did find a solder joint on a pcb giving the no power problem once. So I put a link in to the terminal block to fix it. You could have a joint problem.

 

[vick1]

Cheers oilman, in fact thanks to everyone else too. Any particular terminal block or is it dependant on which joint has 'gone'. sorry guys, I must sound a right 'Homer'.

 

[cjb1971]

Where the timer plugs into the terminal block u can unplug it and link out the ch/dhw with the 240v-this will then tell you if its a problem with timer or if it is somewhere else.

 

[vick1]

Where the timer plugs into the terminal block u can unplug it and link out the ch/dhw with the 240v-this will then tell you if its a problem with timer or if it is somewhere else.

Sorry to be a dumb##s, just want to check that you mean putting a link between the 240v and ch terminal on the clock connection and another beween 240v and hw terminal on the clock connection??

Cheers

 

[cjb1971]

Where the timer plugs into the terminal block u can unplug it and link out the ch/dhw with the 240v-this will then tell you if its a problem with timer or if it is somewhere else.

Sorry to be a dumb##s, just want to check that you mean putting a link between the 240v and ch terminal on the clock connection and another beween 240v and hw terminal on the clock connection??

Cheers

Yeah u can do it to either one or the other or both.