I'm considering upgrading to a digital programmable thermostat for my house. This old analog model is too inaccurate so it's time to move on. Are there any considerations for use with an OWB?
Which thermostat for use with an OWB?
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velvetfoot
Minister of Fire
I've been fooling around with getting my Ecobee thermostats to fire up the oil boiler in parallel when the pellet boiler can't keep up: https://www.hearth.com/talk/threads...ler-with-an-ecobee-smartsi-thermostat.147270/ . I
I have a couple of Ecobee SmartSi wifi thermostats, so they can be controlled over the Internet. Although it will function without an internet connection, that was one of the big attractions to me. Although, It's accurate and adjustable, but not geared specifically to hydronic heat. While I only have baseboards and not radiant distribution, I can't help but wonder what Tekmar has, which seems to specialize in hydronics, but so far I've resisted going to their web site.
My thermostats will send me an email alert when the temperature drops to a specified level and also if the 'mother ship' determines that the system isn't responsive.
I have a couple of Ecobee SmartSi wifi thermostats, so they can be controlled over the Internet. Although it will function without an internet connection, that was one of the big attractions to me. Although, It's accurate and adjustable, but not geared specifically to hydronic heat. While I only have baseboards and not radiant distribution, I can't help but wonder what Tekmar has, which seems to specialize in hydronics, but so far I've resisted going to their web site.
My thermostats will send me an email alert when the temperature drops to a specified level and also if the 'mother ship' determines that the system isn't responsive.
Yeah I'd be tempted by being able to remotely control / check on things. I do have slight security concerns though. It was the "not geared specifically to hydronic heat" comment that I was wondering about. How much does that really matter I guess and/or what improvement would there be for something that is?
I have oil, radiant in the basement, wood insert and wood stove; OWB is the latest addition that isn't fully hooked up yet (hence looking into thermostats now). It will be responsible for house, garage, domestic hot water (and in turn, radiant heat). I have no intention of using oil anymore except for when I'm gone for long periods and hot water during the summer.
It would be pretty cool to have a single setup that could control OWB/radiant/oil (as backup) but I'm guessing that would be on the more expensive side. I guess a stop-gap would be getting a few wifi enabled thermostats and call it a day.
I haven't heard of Tekmar but hit their site; seems... expensive and above my head. I did gather that it's likely more suited to the purpose though.
Thanks for the link, I'll have a read.
I have oil, radiant in the basement, wood insert and wood stove; OWB is the latest addition that isn't fully hooked up yet (hence looking into thermostats now). It will be responsible for house, garage, domestic hot water (and in turn, radiant heat). I have no intention of using oil anymore except for when I'm gone for long periods and hot water during the summer.
It would be pretty cool to have a single setup that could control OWB/radiant/oil (as backup) but I'm guessing that would be on the more expensive side. I guess a stop-gap would be getting a few wifi enabled thermostats and call it a day.
I haven't heard of Tekmar but hit their site; seems... expensive and above my head. I did gather that it's likely more suited to the purpose though.
Thanks for the link, I'll have a read.
velvetfoot
Minister of Fire
My fear is that if I start reading that site, I'll want to buy something. 
Your the person that has to figure out how you're going to use that heat. Radiant in basement means tubing in concrete? That takes a long time to heat up and I imagine would like it if it stayed at one temperature and opposed to any periodic setback. I imagine there are scenarios where the slab temperature is regulated by temperature mixing pumps or whatever-but I'm no radiant heat expert. But still, you can't just turn that down overnight, and if you don't feed your owb for a while and things cool down some, it'll take a while to get it back up to temp.
Are you counting on the owb to heat your whole house with a slab in the basement? It's a little unclear.
Again, I'm no expert on this, but still interesting to think about.
Your the person that has to figure out how you're going to use that heat. Radiant in basement means tubing in concrete? That takes a long time to heat up and I imagine would like it if it stayed at one temperature and opposed to any periodic setback. I imagine there are scenarios where the slab temperature is regulated by temperature mixing pumps or whatever-but I'm no radiant heat expert. But still, you can't just turn that down overnight, and if you don't feed your owb for a while and things cool down some, it'll take a while to get it back up to temp.
Are you counting on the owb to heat your whole house with a slab in the basement? It's a little unclear.
Again, I'm no expert on this, but still interesting to think about.
Yeah, previous owners of the house set the radiant heat (yep, you got it, tubing in concrete) at one temp all winter. Before it was oil heating that water heater providing said heat and I didn't like how frequently the water heater was running so I kept the temp very low.
This year, the plan is to use OWB as primary heat source for the house, including radiant heat via domestic hot water. So while wifi enabled thermostats for the radiant heat is likely overkill, I'd still like to have control over OWB temps and oil, when needed.
This year, the plan is to use OWB as primary heat source for the house, including radiant heat via domestic hot water. So while wifi enabled thermostats for the radiant heat is likely overkill, I'd still like to have control over OWB temps and oil, when needed.
Clarkbug
Minister of Fire
Maybe I missed something, but your radiant heat comes off of your domestic hot water heater?
I know some people do things this way, but it seems like trouble to mix potable hot water with heating water, plus you will be constantly mixing in cold water to the system.
I would consider adding a separate zone to the system only for the radiant floor. Do you also have baseboards or forced air?
Typically the OWB will be set to maintain a temperature and that doesn't change. Radiant can be a number of different control techniques, either a slab sensor or room sensor.
I know some people do things this way, but it seems like trouble to mix potable hot water with heating water, plus you will be constantly mixing in cold water to the system.
I would consider adding a separate zone to the system only for the radiant floor. Do you also have baseboards or forced air?
Typically the OWB will be set to maintain a temperature and that doesn't change. Radiant can be a number of different control techniques, either a slab sensor or room sensor.
Yeah, radiant heat is off domestic hot water. That's the way the house was done. I've heard people say it can cause problems but without further detail. I actually rarely used the radiant because I felt my hot water tank was always running (I too chalked that up to always introducing cold water).
When the OWB was being installed they decided to put a plate exchanger for the hot water tank to leave everything as-is in terms of fall-back. The alternative (putting a separate loop off the OWB specifically for the radiant heat would have meant that I'd have no radiant heat when the OWB wasn't burning (i.e. being away from home for a while etc. At least with this setup I can flip a switch and fall back to oil.
Oil furnace / forced air. There are two room sensors in my basement that control the radiant heat. As for the OWB, a relative of mine that also has an OWB says he manually turns down the thermostat at night and is considering getting a programmable (preferably wifi enabled) one to handle that.
If money weren't any concern, I'd look into getting multiple wifi enabled thermostats so I could control oil and furnace remotely, independently.
I started taking a closer look at the ecobee 3 with the remote sensors and I'm wondering how useful that would be with an OWB. I mean they're selling them as super smart devices but really, it just makes your heating source work harder to satisfy all settings throughout your house. To me what would be really smart is if it could actually control how much heat gets to each room rather than excessively heat the whole house just so a specific room hits a certain mark. I'm just day dreaming.
When the OWB was being installed they decided to put a plate exchanger for the hot water tank to leave everything as-is in terms of fall-back. The alternative (putting a separate loop off the OWB specifically for the radiant heat would have meant that I'd have no radiant heat when the OWB wasn't burning (i.e. being away from home for a while etc. At least with this setup I can flip a switch and fall back to oil.
Oil furnace / forced air. There are two room sensors in my basement that control the radiant heat. As for the OWB, a relative of mine that also has an OWB says he manually turns down the thermostat at night and is considering getting a programmable (preferably wifi enabled) one to handle that.
If money weren't any concern, I'd look into getting multiple wifi enabled thermostats so I could control oil and furnace remotely, independently.
I started taking a closer look at the ecobee 3 with the remote sensors and I'm wondering how useful that would be with an OWB. I mean they're selling them as super smart devices but really, it just makes your heating source work harder to satisfy all settings throughout your house. To me what would be really smart is if it could actually control how much heat gets to each room rather than excessively heat the whole house just so a specific room hits a certain mark. I'm just day dreaming.
Clarkbug
Minister of Fire
The issue with the radiant and your hot water heater is that you can grow some nasty stuff in the system when you have warm water sitting in the dead leg of a pipe. There is potential for legionella to grow and then you aerate it when you shower.
So while open systems can work fine, they also make some designers nervous.
Because of the thermal mass of the slab, I'm sure your heater ran a lot. It's a big load at once, and the burners arent always that big on water heaters.
I see a similar potential issue with turning down the OWB. They usually have a lot of water on board, so you have to heat all of that stored water back up each morning. While it reduces standby losses, and lets you have a cleaner morning burn, I'm not sure if it saves you much wood.
Not saying it won't work, just don't know how much gain it will get you.
EDIT: just thought about this more and an outdoor air temp reset would be more useful than a night setback thermostat.
So while open systems can work fine, they also make some designers nervous.
Because of the thermal mass of the slab, I'm sure your heater ran a lot. It's a big load at once, and the burners arent always that big on water heaters.
I see a similar potential issue with turning down the OWB. They usually have a lot of water on board, so you have to heat all of that stored water back up each morning. While it reduces standby losses, and lets you have a cleaner morning burn, I'm not sure if it saves you much wood.
Not saying it won't work, just don't know how much gain it will get you.
EDIT: just thought about this more and an outdoor air temp reset would be more useful than a night setback thermostat.
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