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James, Developer
Category: HVAC
Satisfied Customers: 9447
Experience:  I have a portfolio of renovated houses, including DIY projects from installing bathrooms and new heating systems to rewiring.
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Worcester star 15 Ri, installed 07/2013, nest thermostat

Customer Question

Worcester green star 15 Ri
JA: What's the brand and model of your HVAC unit? How old is it?
Customer: installed 07/2013
JA: How long has this been going on? What have you tried so far?
Customer: nest thermostat says your equipment has no power
JA: Anything else we should know to help you best?
Customer: Blue light is on
Submitted: 13 days ago.
Category: HVAC
Customer: replied 13 days ago.
Will you send some suggestions soon ?
Expert:  James replied 13 days ago.

Hello and welcome to JustAnswer! This is James, I'm an appliance repair technician with over 10 years of experience, and I'll be assisting you today.

Sorry to hear your appliance is having issues, please stand by while I find the answer for you, this is not an immediate service however I will try and respond as soon as possible.
To confirm is it the Nest or the boiler which has no power?

Customer: replied 13 days ago.
File attached (PZP12V2)
Customer: replied 13 days ago.
Tried switching the boiler on and off the fan moves for a second and then all silent with green light on all times
Expert:  James replied 13 days ago.

The green lamp on the boiler means the boiler is on and heating, where the light goes to blue its in standby.

I would first reset the boiler condition turn the temp control knob (right hand knob) of the boiler to reset (turn it fully anti clockwise until it stops), wait 5 seconds then set to its original position eg 1 o'clcok. Then wait 1 minute and then I would reset (power off and on) your Nest and see if the fault comes back.

It was a pleasure to assist you today. I hope the above answers the question. If you have any follow up questions then please let me know.

Customer: replied 13 days ago.
I did watch a YouTube video and did exactly that without results
There is no heat or hot water no working sound from the boiler
Customer: replied 13 days ago.
Thermostat does not work
Customer: replied 13 days ago.
There is no supply of power to the WiFi equipment or heating system from the control box
Expert:  James replied 13 days ago.

Right depending on how the Nest box has been configured it should be getting power from the boiler, so we have power going to the boiler it suggests the Nest box has failed. I would check next to the Nest hub encase its on a separate power supply and has a fused spur which has blown and needs a new fuse.

It looks like that shown in the video here.

Customer: replied 13 days ago.
Where is the video or picture please
Expert:  James replied 13 days ago.

Sorry it should have said picture not video, the image can be viewed at the link below

Customer: replied 13 days ago.
There is no power to pump wifi or the valve
Expert:  James replied 13 days ago.

You cant use an electrical driver to test a circuit, you need a multi meter.

Where confident power is not getting to the unit you need follow back the wire from your hub to the boiler and see where it terminates as it suggests as mentioned above there is another fused spur which stopping power going to the appliance.

It was a pleasure to assist you today. I hope the above answers the question. If you have any follow up questions then please let me know.

Customer: replied 13 days ago.
I checked the fuse it is ok
Expert:  James replied 13 days ago.

Ok so if your getting power from this and the wire goes to your Hive hub then you either not traced the wire back to this, have a break in the cabling or not measuring the voltage arriving at the hub correctly.

Customer: replied 13 days ago.
Can local assistance be provided by you ?
Customer: replied 12 days ago.
Expert:  James replied 12 days ago.

No JA only provide online advice, you can find a local heating engineer using a service such as here if you are unable to track back the cables from your Nest back to the boiler.