electric floor heat question

[REY_off]

So maybe I missed this, but do you run floor heat using the tankless water heater? I read on their website that is becoming more common, and have heard that from others as well. $1200 is definitely better than 3 to 4K!!!

yes, I am. See my first and last post.

 

[bigbrad123]

Hey bigbrad what are we talking about as far as heating bill? Not total electric but just heating if you can separate on you bill and if you can't what is your total bill during a typical winter heating month?

I am not sure how changing out a thermostat will lower your costs. If you keep temp where you want it, a better newer thermostat will keep it closer with less variation but I fail to see how it will save you money unless it is programable so you can automatically adjust it down during hours when the comfortable temp is not needed. BUT then you run the risk that the boiler system will take a bunch of time to readjust to comfortable temp range. If it keeps up with the heat needed for your comfort then your problem is with the BTU cost to keep it where you want. Insulation, wind breaks, windows, types of power/boiler.........IMHO

Moved into the house in mid December last year. Electric bill was $400 in January. Guessing $200 or $250 of that was floor heat. Maybe that isn't out of the norm but I guess I always read how it was so efficient so it surprised me.

Wasn't sure about the thermostat either other than if I get a new one that has a floor sensor, the thermostat would go off the floor temp instead of the air temp like it does now.

Might look into a gas tankless water heater now as a possible option.

 

[327]

Adding a off peak meter should be fairly inexpensive to install. I would bet it would pay for itself in the first winter. But gas would
would be cheaper to run. I have an electric boiler in 30x32 shop on a off peak system and it is still fairly expensive to operate "about150 a month" but I sure like it.

 

[Mocha]

Correct me if I'm wrong but your total electric bill for 2400 sq feet was $400. How much was your gas bill for the same month?

 

[bigbrad123]

Correct me if I'm wrong but your total electric bill for 2400 sq feet was $400. How much was your gas bill for the same month?

Can't remember exactly, but I think my gas bill was around $75 to $100. Maybe the $400 is normal, but I guess it was just a shock to me since I all I heard was how efficient it was. Once I quit using the floor heat, my bill went back down to about a $100.

 

[Mocha]

So if my calculations are correct your total heating bill for January would be $375 for 2400 sq feet. That is not to bad compared to north Central MN. Our electric rates must be considerable higher than yours. One thing to remember is since your heating the entire lower lever with floor heat your gas forced air portion of the bill is lower than it would normally be since heat rises and helps with the heat load on your second level. My general service meter bill with out any heating or cooling is always around $165/month. Is your home west/norhtwest wind exposed?
One more thing as far as temp prob in the slab.....I personally do not care if I have one or not, I don't, because I keep the room temp where we are comfortable and it does not matter what the thermostat says.

 

[Allen]

I'd like to try a couple other options before breaking down and spending $3 or $4k.

Not to be a smartass, but what I heard when I read this was: I'd rather gamble by spending $500 to $2,000 and be disappointed before I pony up the $3 - $4k.

Especially if money is a concern, this makes a pretty convincing case to avoid being unhappy with the cheap alternatives that will push you into eventually spending $4,500 to $6,000.

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FWIW, the little experience I have with offpeak suggests you should start with that before worrying about any major remodels.

 

[bigbrad123]

Not to be a smartass, but what I heard when I read this was: I'd rather gamble by spending $500 to $2,000 and be disappointed before I pony up the $3 - $4k.

The issue is maybe I won't be disappointed by spending much less?? Maybe that will significantly help me with my electric bill by trying a couple other basic things first like a different thermostat before dropping a bunch of cash on as gas boiler. Never had off peak on anything before, so I also don't know how much I'll like that. That's why I am asking the questions. Smartass. :;:

 

[Allen]

I think the only time I'd try a new thermostat design is if the building wasn't being heated to my liking. e.g., too big of a temp swing, or want to go to a programmable style. Maybe I'm missing something here as I've not had to delve into the fine details of a floor heat system, but how is a new style thermostat going to produce the performance (assuming you like the heat level) that you already have and yet save you some money?

FWIW, I do enjoy these threads because I hope to build a new place in a few years and it helps me learn, so I'm not just out for a (s)troll.

Any thought put into a geothermal system? I know they are darn expensive initially, but wonder if a retrofit would be cost effective.

 

[bigbrad123]

I think the only time I'd try a new thermostat design is if the building wasn't being heated to my liking. e.g., too big of a temp swing, or want to go to a programmable style. Maybe I'm missing something here as I've not had to delve into the fine details of a floor heat system, but how is a new style thermostat going to produce the performance (assuming you like the heat level) that you already have and yet save you some money?

FWIW, I do enjoy these threads because I hope to build a new place in a few years and it helps me learn, so I'm not just out for a (s)troll.

Any thought put into a geothermal system? I know they are darn expensive initially, but wonder if a retrofit would be cost effective.

Thinking of a programmable thermostat so the current thermostat isn't always kicking in the boiler every time the air temp falls a degree or two. Unlike a gas forced air system, its hard to know how often my boiler is kicking in. It was a recommendation of an electrician friend to try a programmable thermostat instead of the old round mercury one I have. Ideally I'd like the boiler to not kick on at all when we are gone all day at work. Again, no idea if that will actually help.

 

[Retired Educator]

Not an expert on floor heat other than making sure the insulation is done properly. It also seems to me that floor heat is designed for off-peak rates. Once the floor is heated that heat will be retained for some time thus allowing for continued heat while the heat source is actually turned off. For electric off peak it should be simple to check with your electric company to confirm what the off peak rates would be. I'm sure they should be able quote you a per KW rate. That will tell you how much you can save by switching to off peak.

People I know with floor heat seem to love it. For shops they keep the heat much lower than their house (50-60) because the heat on the floor just makes it feel warmer. Then in a house where the basement is typically concrete, floor heat allows a floor covering other than carpet. Pretty sure correct installation is a major portion of satisfaction.

 

[red eyed devil]

electric boilers r expensive to run replace it with a gas water heater 40 gallon 40000 btu should work fine for a basement

 

[bigbrad123]

electric boilers r expensive to run replace it with a gas water heater 40 gallon 40000 btu should work fine for a basement

Any recommended brands?

 

[stalker]

I was pondering this and a few questions and a couple of comments came to my mind.

Comments:

Gas water heaters are cheap. I replaced the one in my house for about $700. Mine is a power vent version and I got it on sale at Fleet Farm. I don't remember the brand. They are cheap, but only last about 10 years. I think you can get condensing style gas water heaters also, but I would guess they are going to cost more and be more trouble down the road.

I looked at replacing my water heater with a tankless - which would be similar to a boiler - but it didn't justify the extra cost. Tankless units are going to be double and my hot water costs about $5 a month with natural gas.

Questions:

Would you need to reconfigure the water heater to be used in a floor heat system. Pumps work best with some head pressure on them. So, would you change the drain valve to be the outlet of the water heater? If you plumb it the way they are designed, you would be pumping off the top and that's where any air would get trapped.

 

[bigbrad123]

I was pondering this and a few questions and a couple of comments came to my mind.

Comments:

Gas water heaters are cheap. I replaced the one in my house for about $700. Mine is a power vent version and I got it on sale at Fleet Farm. I don't remember the brand. They are cheap, but only last about 10 years. I think you can get condensing style gas water heaters also, but I would guess they are going to cost more and be more trouble down the road.

I looked at replacing my water heater with a tankless - which would be similar to a boiler - but it didn't justify the extra cost. Tankless units are going to be double and my hot water costs about $5 a month with natural gas.

Questions:

Would you need to reconfigure the water heater to be used in a floor heat system. Pumps work best with some head pressure on them. So, would you change the drain valve to be the outlet of the water heater? If you plumb it the way they are designed, you would be pumping off the top and that's where any air would get trapped.

Good questions. I have no idea. I've read both opinions on using a tankless water heater for floor heat. I've read places that say its just fine (here included) and other websites where its not recommended. I've heard enough people say it works just fine and is also efficient so it's definitely a direction I am considering going. Purchased a new digital, programmable thermostat today specially made for hydronic floor heat.

 

[red eyed devil]

Any recommended brands?

state and Bradford white are the best I would buy the cheapest one from menards lowes ect.

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leave the elec boiler installed and use water heater as buffer tank set elec boiler to lower temp than water heater for excess load example first start up of the year

 

[327]

Cases county has member service people to answer your questions on off peak rates etc
they may even install the off peak set up for you for a fee I'm sure.

 

[REY_off]

electric boilers r expensive to run replace it with a gas water heater 40 gallon 40000 btu should work fine for a basement

I'm not saying that this wont work, because I've seen examples of many systems that run with a regular gas fired water heater and the owners are happy with them, but to me it just seems counter productive in this application.

The whole idea of floor heat is to heat the slab of concrete to an even temperature before the pump stops putting hot liquid through the tubes in the floor. Once the slab temperature set point is achieved, the slab (assuming it is insulated correctly) should hold that temp for a reasonable amount of time, giving off heat to the room the whole time.

When using a regular water heater. Whenever that slab temp is achieved, and the pump stops, you are now burning up BTU's to keep that tank of water hot until the pump kicks in again. All those BTU's are wasted. With how expensive the overhead is to install these systems, most people try to run them as efficiently as possible. In the OP's case, I guess that doesn't matter much to him, because he bought the house as is.

If it was me, I would collect as much info on how these systems are supposed to run, and do a once over on your current system to make sure everything seems right. If everything checks out I would get a price on installing off peak power vs buy a new gas fired tankless water heater. If it is located in your basement, I would go with a condensing tankless heater because they can be vented with PVC, much similar to the High Efficiency furnaces being installed now days, which gives you more options for installation.

One other thing I would check is if you have a multiple speed pump, and the inlet and outlet temps at the manifold. IIRC, most people try to achieve 120 degree inlet temp, and a 90 degree outlet temp.

 

[bigbrad123]

Cases county has member service people to answer your questions on off peak rates etc
they may even install the off peak set up for you for a fee I'm sure.

I already went to Cass Co. Electric and spoke with them. THey gave me the rates too for off peak. They said I needed to have my electrician install the off peak meter. I spoke with a guy (who is an electrician) who I know well about how much he'd charge me to install it. He said it would be "around $500, maybe a bit less". So I guess my issue at this point is whether I go with off peak or do I put that cash toward a nice gas water heater that could be more efficient and cheaper than a gas boiler.

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I'm not saying that this wont work, because I've seen examples of many systems that run with a regular gas fired water heater and the owners are happy with them, but to me it just seems counter productive in this application.

The whole idea of floor heat is to heat the slab of concrete to an even temperature before the pump stops putting hot liquid through the tubes in the floor. Once the slab temperature set point is achieved, the slab (assuming it is insulated correctly) should hold that temp for a reasonable amount of time, giving off heat to the room the whole time.

When using a regular water heater. Whenever that slab temp is achieved, and the pump stops, you are now burning up BTU's to keep that tank of water hot until the pump kicks in again. All those BTU's are wasted. With how expensive the overhead is to install these systems, most people try to run them as efficiently as possible. In the OP's case, I guess that doesn't matter much to him, because he bought the house as is.

If it was me, I would collect as much info on how these systems are supposed to run, and do a once over on your current system to make sure everything seems right. If everything checks out I would get a price on installing off peak power vs buy a new gas fired tankless water heater. If it is located in your basement, I would go with a condensing tankless heater because they can be vented with PVC, much similar to the High Efficiency furnaces being installed now days, which gives you more options for installation.

One other thing I would check is if you have a multiple speed pump, and the inlet and outlet temps at the manifold. IIRC, most people try to achieve 120 degree inlet temp, and a 90 degree outlet temp.

Thanks for the advice. I think I may get someone over once I start using floor heat and see if they can check everything over to if everything looks good and maybe get some more advice from them as well.

Now the big question is who in Fargo is really good at installing/maintaining floor heat systems and isn't going to just come in and try to sell me a big old gas boiler.

 

[REY_off]

I already went to Cass Co. Electric and spoke with them. THey gave me the rates too for off peak. They said I needed to have my electrician install the off peak meter. I spoke with a guy (who is an electrician) who I know well about how much he'd charge me to install it. He said it would be "around $500, maybe a bit less". So I guess my issue at this point is whether I go with off peak or do I put that cash toward a nice gas water heater that could be more efficient and cheaper than a gas boiler.

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Thanks for the advice. I think I may get someone over once I start using floor heat and see if they can check everything over to if everything looks good and maybe get some more advice from them as well.

Now the big question is who in Fargo is really good at installing/maintaining floor heat systems and isn't going to just come in and try to sell me a big old gas boiler.

My advice if you cant find someone with a good reputation on hydronic heating, get an account over at garagejournal.com. Start a thread and post of picture of your whole system setup. I've seen threads where the guys over there have walked people through fixing common installation mistakes by just looking at a picture of the system. There really is a wealth of knowledge on that site.

Not sure how many people are familiar with the googles ability to search for things on a specific website, but I've used it a lot for websites who's built in search feature was not so great, aka: old fishingbuddy.com. I also use it a lot for garagejournal.com.

enter keywords followed by site:website.com

example would be - floor heat site:garagejournal.com or backyard beehive site:fishingbuddy.com

https://www.google.com/webhp?source...-8#q=floor+heat+set+up+site:garagejournal.com