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The hydronic floor system that we put into our house has tremendous efficiency and long term cost of ownership is very good. This is a great way to generally heat your home and make your floor a bit warmer. Coupled with foam insulation, it makes for very inexpensive and very comfortable living in the winter. The cost of initial install in a new house build is definitely pricey however.
These issues aside, my system came with 5 two-wire thermostats. One wire leads to R and the other to W on the simple thermostats they provide. This is all well and good except I wanted Hydronic floor control with my Control4 Thermostats.
So here is the step by step process I went through to achieve this:
1. You will need a "common" power wire from the circuit board of your floor heating system. This is fairly easy, especially if they wired your thermostats with at least 4-conductor wire. If not, then you are screwed and have to run new wire to your thermostats... this could be really easy or really hard. In my case I had the extra wire, and I wired it to the common lead off my control board. You turn off the "power stealing" feature of the thermostat.
2. So I thought it would be that simple... Red wire to R, White wire to W1, and C to the common lead on my control4 thermostat. This is in fact the correct way to wire the thermostat. In fact, the control4 manual says it will work with heated floor systems. However, as soon as my relay clicked in the thermostat to activate the valve to my heated floor zone, the thermostat would turn off. Just to be sure it just wasn't this brand of thermostat, I checked a honeywell wifi thermostat and it did the same thing. After some research it turns out that sometimes when a valve closes, you might actually steal all the power leaving none for the thermostat... it appears this is what was going on more or less.
3. Next step: buy an isolation transformer circuit. Here is a 3 zone version for your reference. I have 5 zones so I bought two boards.
SKU:IR882 Brand: Argo
The instruction sheet made it very easy to setup up this circuit in between my thermostat and my hydronic floor controller board. You do need to do some wiring but there is no soldering involved since it is all screw-tight connectors.
4. Now the control4 thermostats work great and I can now coordinate my AC/cooling/forced air heating with my heated floor while also coordinating with outside air temperature. I find that outside temperature is a better variable to decide if the heated floor should be on. Once that is settled you can be sure that the AC/cooling is definitely off any time the heated floor is on. Really the point is to be able to set a temperature that you like and keep the house that temp the whole year round while not overlapping the cooling and heating systems and consequently wasting money.
This project can reasonably be done by a DIY with some basic understanding of wiring and electricity safety. Otherwise, just have your hydronic floor folks put the isolation transformer in for you. Your control4 person can take care of the thermostat integration.
Honestly I think the hydronic floor circuit should come with high quality isolation relays... I have no idea why they don't since there is no real downside.
For those building a new hydronic floor, seriously consider putting the thermostat boxes at the control board and do remote thermostat wires. This will give you a cleaner install and nobody can mess with the system. Place the thermostat wires for the AC system along the same zones as the heated floor. Also put the hydronic thermostats and the AC thermostats together so that they coordinate better without overlap (where both systems are on and fighting each-other).
For the most part, I feel that home AC equipment is antiquated from the control perspective. They should all be IP controlled as far as I'm concerned. A nice Cat6 cable to your thermostats and interconnectivity between AC, hydronic floor, etc would be the most plug and play. I suppose this won't happen any time soon.
These issues aside, my system came with 5 two-wire thermostats. One wire leads to R and the other to W on the simple thermostats they provide. This is all well and good except I wanted Hydronic floor control with my Control4 Thermostats.
So here is the step by step process I went through to achieve this:
1. You will need a "common" power wire from the circuit board of your floor heating system. This is fairly easy, especially if they wired your thermostats with at least 4-conductor wire. If not, then you are screwed and have to run new wire to your thermostats... this could be really easy or really hard. In my case I had the extra wire, and I wired it to the common lead off my control board. You turn off the "power stealing" feature of the thermostat.
2. So I thought it would be that simple... Red wire to R, White wire to W1, and C to the common lead on my control4 thermostat. This is in fact the correct way to wire the thermostat. In fact, the control4 manual says it will work with heated floor systems. However, as soon as my relay clicked in the thermostat to activate the valve to my heated floor zone, the thermostat would turn off. Just to be sure it just wasn't this brand of thermostat, I checked a honeywell wifi thermostat and it did the same thing. After some research it turns out that sometimes when a valve closes, you might actually steal all the power leaving none for the thermostat... it appears this is what was going on more or less.
3. Next step: buy an isolation transformer circuit. Here is a 3 zone version for your reference. I have 5 zones so I bought two boards.
SKU:IR882 Brand: Argo
The instruction sheet made it very easy to setup up this circuit in between my thermostat and my hydronic floor controller board. You do need to do some wiring but there is no soldering involved since it is all screw-tight connectors.
4. Now the control4 thermostats work great and I can now coordinate my AC/cooling/forced air heating with my heated floor while also coordinating with outside air temperature. I find that outside temperature is a better variable to decide if the heated floor should be on. Once that is settled you can be sure that the AC/cooling is definitely off any time the heated floor is on. Really the point is to be able to set a temperature that you like and keep the house that temp the whole year round while not overlapping the cooling and heating systems and consequently wasting money.
This project can reasonably be done by a DIY with some basic understanding of wiring and electricity safety. Otherwise, just have your hydronic floor folks put the isolation transformer in for you. Your control4 person can take care of the thermostat integration.
Honestly I think the hydronic floor circuit should come with high quality isolation relays... I have no idea why they don't since there is no real downside.
For those building a new hydronic floor, seriously consider putting the thermostat boxes at the control board and do remote thermostat wires. This will give you a cleaner install and nobody can mess with the system. Place the thermostat wires for the AC system along the same zones as the heated floor. Also put the hydronic thermostats and the AC thermostats together so that they coordinate better without overlap (where both systems are on and fighting each-other).
For the most part, I feel that home AC equipment is antiquated from the control perspective. They should all be IP controlled as far as I'm concerned. A nice Cat6 cable to your thermostats and interconnectivity between AC, hydronic floor, etc would be the most plug and play. I suppose this won't happen any time soon.