Heatslave 15/19 DHW but no CH?

[Balmeadie]

Hi my actuator head isn’t moving when I call for CH. I hear the control board click but the lever on the head doesn’t move. If I shift it manually and lock it in place I get CH flow. I’ve replaced the synchron Motor and checked the valve spindle moves freely but still no joy! Can the mechanical part of the head fail. The DHW seems very hot as well but may not be related. Any help much appreciated.

 

[CBW]

IT could be that the microswitch isn’t making. What valve is it?

 

[ericmark]

My Heat Slave all controls are external and DHW is thermosyphon with no valve for DHW only valves for central heating zones together with two pumps.

So what is needed is more information about the system, I considered using a thermostat on the DHW with a motorised valve but was advised against it, seems there are many versions of heat slave and mine is rather an early version with no cool down, so should either be C plan or Y plan, but latter versions changed.

I had a similar problem with my daughters Y Plan gas boiler, turned out to be micro switch in mid position three port valve, could not get micro switch so swapped whole valve. However latching the three port valve to bleed position and it worked, but in summer the radiators got warm. Seems that had been done, and my son-in-law had caught the lever when tiding up, which stopped it working.

 

[JimCrow]

My Heat Slave all controls are external and DHW is thermosyphon with no valve for DHW only valves for central heating zones together with two pumps.

So what is needed is more information about the system, I considered using a thermostat on the DHW with a motorised valve but was advised against it, seems there are many versions of heat slave and mine is rather an early version with no cool down, so should either be C plan or Y plan, but latter versions changed.

I had a similar problem with my daughters Y Plan gas boiler, turned out to be micro switch in mid position three port valve, could not get micro switch so swapped whole valve. However latching the three port valve to bleed position and it worked, but in summer the radiators got warm. Seems that had been done, and my son-in-law had caught the lever when tiding up, which stopped it working.

The OP's 15/19 is a combi boiler.

 

[ericmark]

The OP's 15/19 is a combi boiler.

I did wonder as seems to be many versions.

 

[Balmeadie]

Hi folks, thanks for the quick responses. The micro switch wasn’t making contact so I’ve bent the Flat spring attached to it so when the lever is in the manual (LHS) Position it operates. It’s a Honeywell v4044f1125 5 wire actuator. Whether I’m calling for DHW or

 

[Balmeadie]

CH the lever remains in the mid position. Resistance to the left and slack to the right irrespective of what I’m calling for.
Can you put the 5 pin connector the wrong way round on the PCB? I don’t want to blow a fuse or board trying but not 100% I’ve put it back in the same way!! I Should pay more attention school boy error!!

 

[BoilerBob]

Never mind the clicking when you want ch is the circulating pump running if so the flow switch is jammed in the on position and hw is taking priority over ch which means you may need a new flow switch. Bob

 

[Balmeadie]

Thanks Boilerbob, I think it is, the boiler is outside in an outbuilding so I’ll need to check in the morning but I did think it was strange that it might be circulating constantly. Before the summer I had to move the flow switch to get into the exchanger so it may have had something to do with it. As always you guys amaze me with your Fault finding knowledge Especially given your going purely on descriptions from cretins like myself. Keep up the good work this is a great forum.

 

[BoilerBob]

Been working on oil for over 50 years now started with my uncle when I was 10 years old at weekends the man was a genius. Bob