Honeywell sundial y plan 3 position diverter valve

[perkib]

Hi, this may have already been discussed but my issue may be different. Had a new boxt install 12 months ago. All seemed ok at the time. But now notice radiators down stairs only warm, upstairs really hot. Setup new insurance via homeserve to ensure Worcester Bosch boiler garentee.and they needed to validate system first. Because of the heating issue homeserve won't cover the system but boiler they will. They told me issue is with the diverter valve. Is it worth doing a diy job by replacing the whole unit, not just the motor and not the valves on the pipes itself because to replace those involves draining the system down and would need a plumber for that. Rather than just replace the motor, replace the whole top unit excl what it's attached to

 

[perkib]

I've played with the leaver at the side which seems floppy. No difference, still hot upstairs, warm down. Seems even when just ch on, system still heats hw

 

[perkib]

Hw, that's hot water tank in airing cupboard

 

[CountryFan]

If the hot water is being heated when not being asked for then it’s likely stuck in mid position. Depending on the age not all heads are replaceable, if unsure post a photo. If it is replaceable then you can remove the head and test the spindle - which will then indicate whether the whole valve or just the actuator

 

[perkib]

 

[perkib]

 

[perkib]

Photos posted

 

[CountryFan]

Photos posted

That looks like the older type, which means you have to drain to maintain, so you might as well do the full shebang

 

[Exedon]

That looks like the older type, which means you have to drain to maintain, so you might as well do the full shebang

As above that valve is ancient no raised dot on lid.
I would personally replace with 2 zone valves (s plan) much better system.