One on One Advice - Y Plan Behaviour

[LoweLight]

(oh BTW thank you everyone for your generosity so far)

 

[terryplumb]

I can't see anything untoward from the wiring centre , not that it gives absolute clarity. However ,if the system worked last winter ,and nothing has been done at the wiring centre since ,I would assume the problem is the controls or the 3 port valve itself.
Testing at the wiring centre for voltages present at various terminals , in conjunction with programmer /cylinder stat and central heating stats status would be required to establish exactly where the problem is.
Can you confirm the following...
1. The cylinder stat has been checked ,as per your task for today.
2. when the central heating stat is turning the boiler on/ off ,what are the programmer settings whilst you manually have the 3 port latched ?

 

[LoweLight]

OK I drew out a diagram based on what is physically wired and it matches up with @ericmark diagram for system wiring except for some differences, but it's getting complex now and I don't want to tear apart a system that isn't mine as a renter. I think the honeywell timer/programmer adds some complexity to this particular setup and I don't know the pinout of the boiler..

Using the diagrams, maybe I'll continuity-test the cylinder stat and the diverter valve.

 

[LoweLight]

I can't see anything untoward from the wiring centre , not that it gives absolute clarity. However ,if the system worked last winter ,and nothing has been done at the wiring centre since ,I would assume the problem is the controls or the 3 port valve itself.
Testing at the wiring centre for voltages present at various terminals , in conjunction with programmer /cylinder stat and central heating stats status would be required to establish exactly where the problem is.
Can you confirm the following...
1. The cylinder stat has been checked ,as per your task for today.
2. when the central heating stat is turning the boiler on/ off ,what are the programmer settings whilst you manually have the 3 port latched ?

I can do that, I'll get back to you

 

[terryplumb]

What do you mean by .." I don't know the pin out of the boiler" ???

 

[ericmark]

Installation instructions are here see page 36, however likely you would need to removed sealed covers, so not really some thing you should be touching.

 

[LoweLight]

2. when the central heating stat is turning the boiler on/ off ,what are the programmer settings whilst you manually have the 3 port latched ?

Water and Central Heat on, and room thermostat calling for heat:
If I turn off central heat, the latched valve will swing to the hot water side. This is the state that will not recover, I cannot get the valve to automatically swing out of this position
If latched and I turn off water heat, it will swing to full central heat. If I then turn water heat back on, the valve returns to the mid position though the little tab seems to be more to the water heat side, but not fully evidenced by the ability to push the lever and it travels to the mid position again.
This seems correct mostly

 

[terryplumb]

I am getting a bit confused. If the programmer is set to have central heating on ,and DHW ( domestic hot water) Off. And the 3 port set to its Auto position ( not influenced by you manually) your boiler does not fire up at all ,is that basically your problem ?

 

[LoweLight]

I am getting a bit confused. If the programmer is set to have central heating on ,and DHW ( domestic hot water) Off. And the 3 port set to its Auto position ( not influenced by you manually) your boiler does not fire up at all ,is that basically your problem ?

The boiler fires when it's supposed to. My problem is that the zone valve will never move to the middle or to central heat on its own, thus the house will never heat up. I only get hot water unless I move the actuator on top of the valve manually. All this other talk is more detail about my observations of the valve (Daytron MA1) actuator under various input states like cylinder thermostat, room thermostat, and programmer water/central heat on/off.

The room thermostat operates correctly in that it commands heat from the system, but the valve won't move out of the Water side ever unless I move it manually. It then can be manipulated using the timer settings, but if it ever gets into a water only state, it will not move back out. The water pump seems to run continuously.

 

[LoweLight]

Installation instructions are here see page 36, however likely you would need to removed sealed covers, so not really some thing you should be touching.

Agreed though it does give me information on the connections to the boiler. This helps me understand that the wiring may not be properly done but depends on what the timer needs too.. I've not yet looked for that documentation

 

[LoweLight]

What do you mean by .." I don't know the pin out of the boiler" ???

Pinout, the connections to the boiler based on it's terminals etc. Pinout is more of an electronics term showing what each pin on a chip or system board is for. I just used the term for the boiler for simplicity.

 

[terryplumb]

With programmer set for central heating ON and DHW OFF. And the central heating thermostat calling for heat ,there should be 240 v measured between earth terminal and the terminal that holds the grey wire from the 3 port and there should also be 240v measured between earth terminal and the terminal that holds the white wire from the 3 port.
Are you competent to measure these safely on a live circuit ?

 

[oilhead]

Drayton MA1 actuators are the spawn of the devil. Ifit all worked last year and you have made no wiring changes and checked the thermostat operations, both cylinder and room, then there can only be one culprit. If you shop around, you may find it is cheaper to buy a complete valve rather than just a head, then just use the actuator.

 

[LoweLight]

With programmer set for central heating ON and DHW OFF. And the central heating thermostat calling for heat ,there should be 240 v measured between earth terminal and the terminal that holds the grey wire from the 3 port and there should also be 240v measured between earth terminal and the terminal that holds the white wire from the 3 port.
Are you competent to measure these safely on a live circuit ?

I am, and have just done so, 240VAC on both indicating the MA1 is not functioning correctly. I also measured continuity on the cylinder stat and it seems fine as I rotate the knob though I find the attachment strap very hokey.

Next step is to replace the head.

 

[LoweLight]

Drayton MA1 actuators are the spawn of the devil. Ifit all worked last year and you have made no wiring changes and checked the thermostat operations, both cylinder and room, then there can only be one culprit. If you shop around, you may find it is cheaper to buy a complete valve rather than just a head, then just use the actuator.

Lol, I'm getting that impression and per my last post, I'm measuring 240VAC on both terminals when heat is commanded/selected. I would agree the combo is cheaper, will likely go that route and just use the new head.