Replacing the control system... it's a real mess!

[tonymorris24]

Hi all,

I've previously been helped on here by kind people so I'm tackling my next challenge. We have a GSHP (installed by previous owners) that supplies a buffer tank. That all runs OK.

The heating pump and manifold actuators are 'controlled' by three OJ Electronics WLM3s (one master and two slave units).

And here's where I get stuck:

Wired to the OJ boxes are room thimble sensors/thermistors, manual thermostats [I presume disabled] and data cable/cables from a Crestron control system. I think what happens is OJ receives temperature values from the rooms, sends those to Crestron and Crestron returns an open/close signal for each actuator back to OJ to implement.

The Crestron app (I think provided by Ultamation) is six years old and truly, truly terrible. It has set points, set point overrides, no obvious logic and can't be changed without forking out hundreds for a Crestron engineer. Even Ultamation couldn't understand the installation.

The challenge:

• I'd like to be able to control the system via an app, a decent one
• I don't know whether the room thermistors are OK (the readings are erratic via Crestron, but I don't know whether that's Crestron or the sensors), but may have to switch to wireless sensors or something else. The existing thermistors are connected with just two wire, and are badly sited in some places.
• Let's take Crestron out of the equation
• Can I keep the OJ boxes and Rehau actuators?

Any ideas very gratefully received! It's been suggested to rip it all out and put in heatmiser, but I wonder whether there are other options too. Thank you!

 

[ShaunCorbs]

Tbh I would also rip out and install a heat miser

The oj boxes are your programmers of sort and you hafe remote room stats probably bi metal or with logic eg date have you tried removing one to see if there’s no a few more wires stuffed in the wall ?

 

[tonymorris24]

Tbh I would also rip out and install a heat miser

The oj boxes are your programmers of sort and you hafe remote room stats probably bi metal or with logic eg date have you tried removing one to see if there’s no a few more wires stuffed in the wall ?

Hi, thanks for the reply. I've removed one - it's just two wires, unfortunately!

 

[ShaunCorbs]

That’s just an ntc sorry but no stat will wire to that as it’s working off a resistance value

 

[tonymorris24]

That’s just an ntc sorry but no stat will wire to that as it’s working off a resistance value

What if I connected a stat to one end (I like the Tado ones) and the other end into a heatmiser wiring box or similar (instead of the existing thermostat by the OJ box) Thanks!

 

[ShaunCorbs]

What if I connected a stat to one end (I like the Tado ones) and the other end into a heatmiser wiring box or similar (instead of the existing thermostat by the OJ box) Thanks!

It’s not mains rated cable so anything you put on the end would have to be less than 12v

 

[tonymorris24]

It’s not mains rated cable so anything you put on the end would have to be less than 12v

Are normal two-wire thermostats more than 12V? I presume not?

 

[ShaunCorbs]

Yes normally 240v or they use battery’s and then there volt free normally

 

[tonymorris24]

Are normal two-wire thermostats more than 12V? I presume not?

So in summary.. something like this...

(The tado wired thermostats are battery-powered)

 

[ShaunCorbs]

But surely a full wireless heat miser set up would be cheaper than buying 6 tado thermos ? Eg neo air with a uh8 rf

Then you can move the thermos to where you want

 

[tonymorris24]

But surely a full wireless heat miser set up would be cheaper than buying 6 tado thermos ? Eg neo air with a uh8 rf

Then you can move the thermos to where you want

Aren't the heatmiser wireless thermostats about £70/80, the same as Tado?

 

[ShaunCorbs]

Heatmiser neoAir V3, Wireless Smart Thermostat

The Heatmiser neoAir V3 offers a smarter and more convenient way to control your heating and hot water from anywhere in your home when paired with

underfloorheating-direct.com

Works out around 450 ish complete

 

[tonymorris24]

Heatmiser neoAir V3, Wireless Smart Thermostat

The Heatmiser neoAir V3 offers a smarter and more convenient way to control your heating and hot water from anywhere in your home when paired with

underfloorheating-direct.com

Works out around 450 ish complete

Thanks! In reality we have 15 thermostats (sorry I simplified the diagram!)

One manifold has 10 actuators (6 thermostats), another 8 actuators (7 thermostats) and another 2 actuators (2 thermostats). Would you mind letting me know what you think that means I need? Thanks so much!

 

[ShaunCorbs]

I’m guessing you have ufh in 15 rooms ?

 

[tonymorris24]

I’m guessing you have ufh in 15 rooms ?

Yes, some a bit daft.. like a downstairs toilet, and two circuits in the kitchen, each with their own thermostats..

 

[tonymorris24]

Heatmiser neoAir V3, Wireless Smart Thermostat

The Heatmiser neoAir V3 offers a smarter and more convenient way to control your heating and hot water from anywhere in your home when paired with

underfloorheating-direct.com

Works out around 450 ish complete

Also I'd actually prefer not to have the temp shown in each room with adjustment - mobile app with me and my wife is fine! I think heatmiser do wireless air sensors alone but not sure whether they'd work instead? ta

 

[ShaunCorbs]

Also I'd actually prefer not to have the temp shown in each room with adjustment - mobile app with me and my wife is fine! I think heatmiser do wireless air sensors alone but not sure whether they'd work instead? ta

Don’t know on that one best email heat miser