Problem: No hot water from unvented cylinder, although central heating works fine.
Hi All - apologies for the lengthy post but I'm keen to get across as much detail as possible.
I'm a novice, any advise would be really appreciated.
Setup:
Pressurised/unvented cylinder (Tempest)
System Boiler (Worcester)
2 x 2 port motorised Honeywell valves
Nest smart control
General info:
Installed 3 months ago (previously gravity fed) - no problems since now.
Water softener installed 2 months ago - no problems until now.
When turning on HW from the app I can hear the click from the HeatLink.
HW temp set to around 63 degrees, pressure gauge indicated being at 1.5.
Scenario 1:
Turn on HW from the nest app.
- HW icon says ‘on’ but does not go orange as it usually would.
- Boiler does not “fire” up i.e. the green light doesn’t flick on.
- HW 2 port valve stays in the ‘closed’ position i.e. there is resistance when trying to turn it to the manual override function.
= No HW.
The above would suggest a problem with the HW 2-port valve.
However, when I turn the valve to the override ‘on’ position, the boiler still doesn't fire up and still get no hot water.
This suggests a problem with the boiler.
Scenario 2:
I turn on both HW and CH from the HeatLink manual control panel.
- Both icons in the app go orange (as you would expect).
- Boiler fires up, light goes green.
- 2 port valve for CH frees up, HW stays in the closed position.
= CH comes on, but no HW.
Again, this suggests a problem with the HW 2-port valve.
However this is where things get strange:
Following on from Scenario 2:
- I now place the 2-port HW valve in the override position
= I get HW.
- I leave it like this for 10/15 minutes (both HW and CH are on and working).
- Turn both HW and CH off from the HeatLink.
- Take the HW 2-port valve out of the override position.
Now, when I turn on HW from the nest app
= Everything works perfectly; boiler fires up, HW 2-port valve works (gear becomes free and can hear the gear close when turning HW off), app icon goes orange and I get hot water.
The HW now works on request for the whole day and suggests the 2-port is actually working.
So everything appears fine but then the following day I have the same problem. I have to go through Scenario 2 (plus the additional steps) to get things working for the day.
It’s almost like the system needs the initial ‘boost’ from the CH to get things going.
Here's where my thinking is at:
- Upon calling for HW, the 2 port valve should open up straight away even before the boiler doesn't fire up - is this correct (seems to be the case with the CH)?
As this doesn't happen, this suggests a fault with the HW 2 port valve.
BUT why does the HW 2 port valve start working perfectly once I've given the CH an initial boost?
Daily I'm having to go through Scenario 2 (plus additional steps) to get things going for the day in the hope it just starts working like normal the following day
Any help / advise would be greatly appreciated....Thank you in advance!
Hi All - apologies for the lengthy post but I'm keen to get across as much detail as possible.
I'm a novice, any advise would be really appreciated.
Setup:
Pressurised/unvented cylinder (Tempest)
System Boiler (Worcester)
2 x 2 port motorised Honeywell valves
Nest smart control
General info:
Installed 3 months ago (previously gravity fed) - no problems since now.
Water softener installed 2 months ago - no problems until now.
When turning on HW from the app I can hear the click from the HeatLink.
HW temp set to around 63 degrees, pressure gauge indicated being at 1.5.
Scenario 1:
Turn on HW from the nest app.
- HW icon says ‘on’ but does not go orange as it usually would.
- Boiler does not “fire” up i.e. the green light doesn’t flick on.
- HW 2 port valve stays in the ‘closed’ position i.e. there is resistance when trying to turn it to the manual override function.
= No HW.
The above would suggest a problem with the HW 2-port valve.
However, when I turn the valve to the override ‘on’ position, the boiler still doesn't fire up and still get no hot water.
This suggests a problem with the boiler.
Scenario 2:
I turn on both HW and CH from the HeatLink manual control panel.
- Both icons in the app go orange (as you would expect).
- Boiler fires up, light goes green.
- 2 port valve for CH frees up, HW stays in the closed position.
= CH comes on, but no HW.
Again, this suggests a problem with the HW 2-port valve.
However this is where things get strange:
Following on from Scenario 2:
- I now place the 2-port HW valve in the override position
= I get HW.
- I leave it like this for 10/15 minutes (both HW and CH are on and working).
- Turn both HW and CH off from the HeatLink.
- Take the HW 2-port valve out of the override position.
Now, when I turn on HW from the nest app
= Everything works perfectly; boiler fires up, HW 2-port valve works (gear becomes free and can hear the gear close when turning HW off), app icon goes orange and I get hot water.
The HW now works on request for the whole day and suggests the 2-port is actually working.
So everything appears fine but then the following day I have the same problem. I have to go through Scenario 2 (plus the additional steps) to get things working for the day.
It’s almost like the system needs the initial ‘boost’ from the CH to get things going.
Here's where my thinking is at:
- Upon calling for HW, the 2 port valve should open up straight away even before the boiler doesn't fire up - is this correct (seems to be the case with the CH)?
As this doesn't happen, this suggests a fault with the HW 2 port valve.
BUT why does the HW 2 port valve start working perfectly once I've given the CH an initial boost?
Daily I'm having to go through Scenario 2 (plus additional steps) to get things going for the day in the hope it just starts working like normal the following day
Any help / advise would be greatly appreciated....Thank you in advance!