Controlling radiant floor, with a wood stove.

TuckerTerra

Getting ready to go into the third season with my current heating system setup. Overall I am very pleased, but the thermostat controls I am not overly happy with.

I have approximately a 2400 square foot ranch with a daylight basement. Radiant floor heating throughout the basement slab along with first floor, and a forces hot water modine in the garage, and firedplace/woodstove in the living room.

Also have heat pump mini splits, but those I just use for AC, not heat.

On the first floor, I have two zones. The first zone is everywhere except for the master bedroom. The master bedroom has its own zone, which generally speaking I keep set at 60° with the door closed in the winter (we like it cold to sleep)

The radiant for heat is primarily operated by a wood boiler with 500 gal thermal storage. Usually, I am able to run the wood boiler enough in the evening to accumulate enough thermal storage in the tank that it will take it throughout the whole next 24 hours when I'm gone to work. If for some reason the thermal storage or wood boiler can't keep up with the demand, the oil boiler will take over. In the living room of the first floor, we have a wood stove that we run uses a primary heat source in the fall and spring when it's just the night time that we need to heat. We also use it throughout the winter on the colder evenings. Not because the radiant can't keep up, more as a convert/ambiance type of thing. I am only marginally satisfied with my current thermostat control setup. Through reading a lot of suggestions, I ended up going to the tekmar thermostats with the in slab sensors along with the outdoor sensors. (I have no radiant water temperature control other than manual mixing valves. Simply on or off.

I figured I would post on here what I'm unhappy with, and either you guys will tell me a solution, or tell me it's just how it's going to be given my setup

1- the thermostats turn on and off way too much in my opinion. They will click on for 1-2 minutes at a time and then shut off. They aren't even on long enough to cycle the hot water from the thermal storage throughout the floor. If I'm running on oil, it's bad enough that it will shut off before the boiler even gets fully to temp. I have tried adjusting the settings multiple times, but it hasn't seemed to make a difference. Major short cycling, like it is set up for a modulating condensing boiler, and not an oil boiler.

2- with the above statement being said, there is very little rises and drops in temperature for the set point. Which honestly, I don't mind if there is a minor change in temperature within the room, if it increases efficiency of the system by not short cycling it

3- I wish there was an easy way I could set the thermostat on 65 (the temperature we typically keep the house at) and have the system know the woodstove is running, because occasionally in the evenings we'll start the wood stove and it hasn't gotten to the point of putting out a lot of heat and the radiant floor will kick on, and before we know it the system overshoots because of the two sources of heat.

Again, it's probably stupid to run the wood stove with a reading floor heat, but the wood stove we have is extremely efficient and once it gets hot it pumps out he tremendous amount of heat with the minimum would consumption and nothing beats a feeling of a wood stove when it's cold out. However, we are gone throughout the day, I don't want those cooling down to the region it's going to take over. And I know you're not supposed to keep adjusting and floor up and down

4- one thing that drives me nuts about the tech car thermostats is the inability to shut them off. The thermostat I have in my garage will turn the heat on if the garage hits below 40, regardless of what mode the thermostat is set on. I already have freeze alarms in place, so I never worry about the garage dropping the little 32. However, when I'm working on equipment out there with the doors open in the fall, it regularly will get down into the 30s but not in danger freezing. As soon as it hits below 40, regardless of the thermostat setting, the tech bar thermostat kicks on the heat, which drives me nuts when I don't want it to be on.

5- I know the tekmar thermostat seem to be all the rant and rage, but I am just not sure they are truly the best thing. Between the short cycling in the inability to turn them off. Also, apparently I got ones that need a bridge to be controlled with wifi, which I have never done. I don't have much interest in connecting them to Wi-Fi for control, more as monitoring thing since most weekends I am gone.But that's another stupid feature of them in my opinion.