Hive not firing boiler for heating

[Turn7]

Hive sytem has all green lights and no apparent issue .

Will fire up boiler when calling for hot water , but , whilst it was heating fine earlier , it is now now firing boiler when heat called for .

Have tried setting stat to manual and boosting to above temps. Hive shows all ok but no boiler firing ?

[miniman]

Hive doesn’t tell the boiler to fire, it triggers the zone valves and the microswitch in the zone valves tell the boiler to fire. Go manually switch the zone valve and see if the boiler fires.

[Turn7]

Zone valve means TRV ?

[Tymb]

might be the valve on the boiler that directs the water to the radiators not working if your just getting hot water when it’s calling for heat. I think they are normally on a fused spur, check it is on, probably somewhere close to the boiler.

[Turn7]

Just for clarity - not getting HW when calling for heat , I manually switched HW on to check boiler would fire up , which it did .

[xx99xx]

miniman said:

Hive doesn t tell the boiler to fire, it triggers the zone valves and the microswitch in the zone valves tell the boiler to fire. Go manually switch the zone valve and see if the boiler fires.

Mine does. I don't have hive valves on radiators so if you tell hive to tell the boiler to turn on, it should turn on.

[Tymb]

Valve probably looks something like this, I think they are normally plumbed so that the water goes around the hot water circuit when off and then diverts the water around the heating circuit when required. There might be a manual lever where you can open it, some I think have an indicator on top which shows the position it is in.

[miniman]

xx99xx said:

miniman said:

Hive doesn t tell the boiler to fire, it triggers the zone valves and the microswitch in the zone valves tell the boiler to fire. Go manually switch the zone valve and see if the boiler fires.

Mine does. I don't have hive valves on radiators so if you tell hive to tell the boiler to turn on, it should turn on.

It’s not about having Hive TRVs on radiators, I’m referring to the zone valves which are switched by the thermostat / call for heat - they open and then fire the boiler. They will be located with the hot water cylinder if there is one.

[21TonyK]

On the controller theres no green light for Centrl Heating? I guess you've tried the button?

[Tymb]

It’s ages since I installed my mums Hive, I think it has a couple of buttons on the receiver ( tap & flame) that you can press to test the system bypassing the Hive controller.

[miniman]

Find this thing:



There will be two of them.

Watch them while you turn on the heating using Hive. If it whirrs and the little arm moves, it’s working on. But I will bet the arm doesn’t move. Move the arm manually and if the boiler fires, the valve is faulty. It’s a 5 minute job to change.

[Turn7]

xx99xx said:

miniman said:

Hive doesn t tell the boiler to fire, it triggers the zone valves and the microswitch in the zone valves tell the boiler to fire. Go manually switch the zone valve and see if the boiler fires.

Mine does. I don't have hive valves on radiators so if you tell hive to tell the boiler to turn on, it should turn on.

Same here . TRVs all round , but lounge TRV set to max as the hive stat in that room.

[miniman]

Have you found the zone valve pictured above? Regardless of TRVs, Hive or otherwise, there should be 2.

[Turn7]

Ok, this is the only valve in the airing cupboard.

The top lever wasn’t moving when heating called for .

I manually pushed it across to heat, and felt a valve move .

Boiler has now fired up, but the arm doesn’t feel like it la connected to anything ?

[miniman]

Turn7 said:

Ok, this is the only valve in the airing cupboard.

The top lever wasn t moving when heating called for .

I manually pushed it across to heat, and felt a valve move .

Boiler has now fired up, but the arm doesn t feel like it la connected to anything ?

Yep, you need a new zone valve. The arm goes floppy once you push it across. When the call for heat turns off it will (should) return to original position.

[Turn7]

PH solves the problem again , many thanks chaps.

I’ll be getting my take plumber to change that as I hate plumbing jobs .

[miniman]

You may well find the motor head can be removed and replaced without undoing anything water related.

[Turn7]

Whilst that may be possible , my gut instinct says the valve is starting to stick and that’s probably taken the motor out .

The may be wrong , but I’ll assume that it’s a full replacement job.

[Danns]

Nah,

Looks like you have a danfoss HS3, probably 22mm.

Disregarding a wire coming loose elsewhere, by the sounds of it you have a faulty microswitch (3 port working in heat but not hw mode), these can be replaced for about £3, but if you want to save the faff.

Buy yourself a new valve and motor head complete, if it s anything like the 2 port version it s usually cheaper than buying just the motor head valve actuator.

Power off
Take old actuator off, (2 screws) opposite corners
Take new actuator off new valve body
Undo bottom black plate from top white section on both new and old actuators.
Solder wires from old to new noting the position.
Give the brass valve a few turns open closed for good measure.
Reattach with 2 screws

(Also doable by rewiring to wiring centre but mine have moulded plug connectors that I like to keep, enables v rapid diagnosis if you have multiple zones ( 3 heating and 1 DHW on mine)

They have a habit of failing!

Job jobbed for about £35 and you ve got a spare valve body in case that ever seizes up.

ETA you don t need to get wet doing this / no actual plu,bing required. Total time to complete, 20-30 mins on a bad day.

Edited by Danns on Sunday 26th October 22:48

[Turn7]

New valve and actuator fitted today and all is toasty again.

Thanks again for the advice .