I Need Work Hive cylinder stat

[holychihuahua]

Is there a Hive wire less battery interface for an unvented cylinder stat or do you need run a cable back to the control center.

 

[Taylortwocities]

I don't think so.
Surely you need wires? You have to use the stat in the cylinder.

 

[Leesparkykent]

Is there a Hive wire less battery interface for an unvented cylinder stat or do you need run a cable back to the control center.

If getting a cable back is a PITA due to decoration, flooring etc you could use a wireless kit like this.

http://www.NoLinkingToThis/p/honeywell-evohome-hot-water-kit/8406h

 

[holychihuahua]

I don't think so.
Surely you need wires? You have to use the stat in the cylinder.

This unvented cylinder was a replacement for an old copper cylinder. It had a strap on cylinder stat wired to a hive battery powered wireless unit. I thought it would nice and simple if hive did similar unit to connect to the switched live thermostat terminals on the unvented cylinder.
So you say there is no hive wireless device for an unvented cylinder. So i need to run a hot water live from the control center which is two floors below brilliant. Hive really are on the ball with modern plumbing systems.

 

[holychihuahua]

If getting a cable back is a PITA due to decoration, flooring etc you could use a wireless kit like this.

http://www.NoLinkingToThis/p/honeywell-evohome-hot-water-kit/8406h

I have just read this answer months later. The honeywell kit looks perfect thank you. I must have missed this when i read your answer months ago.

 

[telectrix]

I have just read this answer months later. The honeywell kit looks perfect thank you. I must have missed this when i read your answer months ago.

intrigued.not by the hive bit but do you have chihuahuas?

 

[davesparks]

If getting a cable back is a PITA due to decoration, flooring etc you could use a wireless kit like this.

Honeywell Evohome Hot Water Kit - http://www.NoLinkingToThis/p/honeywell-evohome-hot-water-kit/8406h

I don't think thinkmtaht acceptable for an unvented cylinder, unless the system is guaranteed fail-safe I wouldn't trust it for the overheat cutout.

 

[Leesparkykent]

It says it's fine for unvented. After all the cylinder is going to have a PRV.

 

[Taylortwocities]

Agreed, every unvented tank I've seen has an inbuilt over temp but
It's mandatory
for this to be WIRED into the DHW control circuit.

 

[davesparks]

It says it's fine for unvented. After all the cylinder is going to have a PRV.

Unvented cylinders are required to have multiple protection devices, the PRV is one of them but cannot satisfy the requirement on its own.

It only has a sensor suitable for insertion into a sensor pocket of an unvented cylinder, it doesn't provide the required overheat protection.
There would have to be a two port valve operated by the overheat stat on the cylinder to provide the required positive shutoff of the coil. I'll have to go through the unvented regs to check if this has to shut down the boiler too or if it could be an independent valve not connected to the rest of the system.

 

[Taylortwocities]

I think G3 should inserted here.

 

[Leesparkykent]

Unvented cylinders are required to have multiple protection devices, the PRV is one of them but cannot satisfy the requirement on its own.

It only has a sensor suitable for insertion into a sensor pocket of an unvented cylinder, it doesn't provide the required overheat protection.
There would have to be a two port valve operated by the overheat stat on the cylinder to provide the required positive shutoff of the coil. I'll have to go through the unvented regs to check if this has to shut down the boiler too or if it could be an independent valve not connected to the rest of the system.

Good point mate....didn't think about the high limit stat and interlock valve.

 

[davesparks]

Good point mate....didn't think about the high limit stat and interlock valve.

I've had a read of G3 and can't quite work out whether an independent valve which just shuts off the flow to the cylinder but doesn't stop the boiler firing could be deemed to satisfy the requirement.
I wouldn't like to chance it personally

 

[jackhammerJIM]

A 2 port valve connected through the overheat stat is satisfactory unless i have been doing it wrong all these years no need to shut down the boiler

 

[davesparks]

A 2 port valve connected through the overheat stat is satisfactory unless i have been doing it wrong all these years no need to shut down the boiler

It's unusual to see it done that way, all of the ones I have done the two port valve has fired the boiler for hot water demand (so stops firing the boiler for hot water when the valve shuts)
Obviously the heating will still fire the boiler, but only when that valve is open

 

[jackhammerJIM]

sorry dave i interpreted that wrong as in boiler shutdown completely until reset .