I would like to replace my heating system and would like some help with what kind of products I need.
Today I get hot water to our house from district heating. I have hot water radiators in the house. The system is controlled by a heating controller (EVR-C) that open and closes a motorized valve (EVR-M90). The valve is AC 24 V, 15 Nm.
This is the products we use today. I’m sorry the .pdf is in Swedish but maybe it will give some indications what kind of system we have:
I would like to replace the heating controller with a Z-Wave enabled one that uses a indoor temperature sensor instead of the outside temperature sensor we have today. I would also like to controll the heating using our Vera Edge.
Do you really need to replace as much as you suggest?
Not speaking Swedish this is somewhat of a guess but:
The controller monitors outside temperature and pipe temperature to manage whether to open the valve.
The controller provides the 24V for the valve.
Perhaps the only thing you need is a z-wave thermostat to replace the inside stat.
You leave the timer on the controller set to continuous and program your schedules in vera. Vera then sets the thermostat target temperature as required by the schedule.
The thermostat then turns on/off the controller as before but the controller continues to manage water flow based on pipe temperature, outside temperature, etc.
This is on the assumption that a z-wave thermostat is available with contacts out to control the boiler. Otherwise you will need a z-wave thermostat and a z-wave boiler controller to provide the contacts.
This way, if the thermostat with contacts is available you will have a system which is still controllable even if vera crashes for some reason (it will at some point) if you have to have the boiler controller too, look for a thermostat with association class so it can control the boiler without vera.
Hmm… It seems the issue is that my current motorized valve (EVR-M90) is controlled by TRIAC input, not voltage free contacts that the Z-Wave receiver SSR303 offers.
What kind of motorized valve would SSR303 work with?
This is new ground for me so I don’t quite understand the bit about needing “a z-wave thermostat […] with contacts out to control the boiler”?
I don’t have a boiler. My system have a furnace using wood pellets in a nearby barn. The furnace heat water that is stored in hot water storage tanks. The water is then transported to the house through a underground pipe.
The motorized valve (EVR-M90) then release the right amount of hot water into the hot water radiators, depending on the heating controller (EVR-C) that uses a sensor for the outdoor temperature and a sensor that measure how hot the water from the barn is.
I like the idea of just turning the heating controller on and off using a Fibaro wall plug or somthing like that, but I don’t have a boiler?!
Sorry, when I said use the thermostat to control the boiler I meant control your existing EVR-C.
Basically I am suggesting that the oly part you replace is your existing indoor thermostat. By setting your existing controller on continuous, the heating is controlled totally by the thermostat set temperature.
You change the thermostat set temperature via vera according to your own schedule which could be done in Pleg or similar.
As you are only controlling the EVR-C you only need contacts as in your existing thermostat.
I have not researched z-wave thermostats so I don’t know if they come with a set of contacts which can control the EVR-C direct of if the thermostat needs to drive a boiler control unit as you detailed earlier. Perhaps others who use z-wave stats can suggest the ideal type.
As another alternative (and I only suggest as something to investigate) is it possible to leave the existing main valve permanently open and use z-wave TRV’s on every radiator. Never having worked with your type of heating I am only throwing out idea’s for you to discuss.
A bit of quick investigstion shows that z-wave thermostats don’t have contacts in them so you would need a separate boiler controller to ptovidd vontacts into you controller.
One advantage though is that the boiler controller is then mounted where youf existinv thermostat is and picks up ecistinv wiring while new thermostats can be mounted anywhere snd as nany as you like.
Preferred if possible though would still be to leave the water valve on continuously and use thermostatic raditator valves for room control.
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