Hot water only when radiators on - Vaillant 428
Posted: Thu Dec 22, 2022 5:18 am
Hi all, we’ve just moved house and have a conventional boiler (Vaillant ecoTEC Plus 428) with a hot water tank. Always had combi boilers before.
When the heating is on, the water gets hot, but not vice versa. When selecting hot water only via Hive, the boiler doesn’t fire even when the hot water is cold.
I can hear the hot water tank thermostat click when adjusted. It’s set to 55c. The boiler has separate controls for hot water and the radiators, both are set to 60c.
There’s a Honeywell motorised valve to the cylinder which I can operate manually - I’ve heard it close. There’s also a Drayton Zone valve actuator on the flow (no idea what it does) and I’ve seen this move.
I’m happy to pay to get it fixed, but local engineers can’t fit us in until after Christmas.
Would really appreciate suggestions as to what’s going on. Thanks, Steve
Here’s the airing cupboard…there’s lots going on
When the heating is on, the water gets hot, but not vice versa. When selecting hot water only via Hive, the boiler doesn’t fire even when the hot water is cold.
I can hear the hot water tank thermostat click when adjusted. It’s set to 55c. The boiler has separate controls for hot water and the radiators, both are set to 60c.
There’s a Honeywell motorised valve to the cylinder which I can operate manually - I’ve heard it close. There’s also a Drayton Zone valve actuator on the flow (no idea what it does) and I’ve seen this move.
I’m happy to pay to get it fixed, but local engineers can’t fit us in until after Christmas.
Would really appreciate suggestions as to what’s going on. Thanks, Steve
Here’s the airing cupboard…there’s lots going on