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HOT WATER HEATING: How to Use a Tank-Style Water Heater
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Feb 22, 2024
The right kind of tank-style water heater makes a great source of heat for any kind of hot water space heating system. Simple, economical, easy to maintain and reliable. Check out this detailed technical tutorial on how to make it happen. READ MY POPULAR ARTICLES ABOUT: Polyurethane Finish - https://bit.ly/powerbuffing DIY Hoop House Plans - https://bit.ly/hoophouseplans Submersible Pump Installation - https://bit.ly/pumpinstallation Air-Drying Wood Tips - https://bit.ly/wooddrying How to Build a Table - https://bit.ly/tablebuilding How to Stain a Deck - https://bit.ly/deckstain Choosing Waterproof Outdoor Glue - https://bit.ly/exterioradhesives How To Build A Wheelchair Ramp - https://bit.ly/wheelchairrampplans SUBSCRIBE: http://bit.ly/BLRchannel WATCH MY POPULAR VIDEO: How to Cut Perfect Miter Joints https://youtu.be/0wnjJ-Xi5FU WATCH MORE BAILEY LINE ROAD: Winter Tips - https://bit.ly/2rpnUcm
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In this video I want to show you two different methods for using a tank style
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gas-fired water heater to power a hydronic heating system. So that's hot
0:11
water heating, either an in-floor system like you see here or a radiator system
0:17
So this is the tank style heater. One of the advantages of this approach as
0:21
opposed to a boiler is that you've automatically got a feed for domestic
0:27
hot water at taps and fixtures and things. So this line here we've got the
0:31
cold water coming into the tank and then up here we have the hot water going out
0:38
to the taps and fixtures. This is a heat trap here. This is just a 290 degree
0:43
bend and the purpose of that is to stop the hot water from from conducting all
0:50
the way up and and getting wasted by radiating out of the hot water pipe. So
0:55
this stops the conduction from going on so it saves a little bit of energy. We've
0:59
got an expansion tank here because when the cold water goes in it's going to
1:03
expand as it gets hot and in many situations you need a tank. There's a
1:09
membrane in here and there's air in part of it so it can take the expansion
1:15
what's going on. So this approach this side here the domestic side is common to
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the two systems I'm going to be showing you and it's what happens on the other side of the tank that really matters. So here in this simple system we have the
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hot water coming off the tank. In this particular case the tank has two sets of
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heat taps or heat outlets. So the hot water comes off here and it goes around
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and it goes through the hydronic heating system and then back into the tank for
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warming. Now all of this happens when the thermostat calls for heat. So the
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thermostat detects that the room is too cold and it delivers it triggers this
2:02
circulator pump here which starts the flow of water. You'll notice that the
2:06
circulator pump is installed in a fairly low part of the system. This saves a lot
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of trouble because it means you're far less likely to have that pump prevented
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from working by an airlock. I mean there's lots of water down here and that
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pump is going to to pump that water fine. So the thermostat calls for heat, turns
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on the circulator pump, circulates hot water through the system until the room
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is warm and then the thermostat shuts off the pump. So cooler water is
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returning to the tank and the tank has its own aqua stat inside so it will it
2:46
will fire up and keep the water in this tank hot as needed in a kind of a
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separate loop than what's happening here in the room. Now the the simple system is
2:59
good but it can't be used in all jurisdictions because of a potential
3:05
problem and that problem has to do with the fact that in the offseason the water
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that's in the heating side of the system is going to just sit there and
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it's possible that microbes could grow in there because the water is not
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circulating it's sitting there for months on end and some jurisdictions do
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not allow that. So there are ways around the problem and that's what I want to
3:32
show you here. One way around the stagnation problem is to wire in a timer
3:39
like you see here. Now this will activate the circulator pump whether heat is
3:47
called for or not for about 10 minutes each day and that serves to to move the
3:55
water through the hydronic system long before it would ever get stagnant. So in
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the summer when things aren't working you're still going to have that circulator pump kick in and for about 10 minutes the water will circulate
4:10
through. It's actually good for the pump for it to run regularly like that even
4:14
in the offseason and some jurisdictions will say yep that's okay and this simple
4:21
system as I call it is is what you can use in places like that. Now a more
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complicated system that eliminates the need for a timer and any possibility of
4:32
stagnant water is also a possibility and it does have some efficiency and
4:38
performance gains possible as well. So that's what I'm going to show you next
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the more complicated heat exchanger system. Here's the second system I call
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it the exchanger system and you'll see it's got the same tank style water
4:52
heater, the cold municipal water supply coming in, the hot domestic supply coming out. So it handles everything you need in the house. The
5:02
same expansion tank here but the difference is what happens on this side
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The hydronic heating water never mixes with the water in the tank and and the
5:15
way that happens is through this heat exchanger here. So what happens when the
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thermostat calls for heat right here the thermostat triggers two pumps, two
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circulator pumps instead of one. It triggers the circulator pump here which
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circulates the hot water off the top of the tank down through the one side of
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this heat exchanger and then back into the tank at the bottom. Now the second
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circulator pump is also triggered and it circulates the hydronic heating water
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through however the water heat is radiated in the house back through and
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on the other side of the heat exchanger. Now a typical heat exchanger like this a
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flat plate style works really well three by eight inches with about 20 plates. I
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find that sufficient for most houses where I live in a fairly cold part of
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Canada. So the hot water from the tank heats this side of the exchanger and the
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water from the heating system picks up that heat from the other side of the
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heat exchanger. You'll notice that the the cooler water enters here and the
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flow of water runs opposite to the flow through the other side of the exchanger
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That's the way you get the most heat exchange from this arrangement. So why
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would anybody want to do this? Well if if you're not allowed to have domestic hot
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water and heating water mix then this is the system for you. There's another
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advantage too and it has to do with the operating pressure of the heating system
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Now typically the the optimal pressure is anywhere from 15 to 30 psi. So that's
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pressure of the hydronic system and that's measured with a gauge here and
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you can monitor that. If you have a system that's directly connected to the
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water tank as in the simple system I showed you before then you're looking at
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anywhere from maybe 40 to 60 psi. That's you know typical municipal water
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pressure and that's somewhat higher than it should be for maximum pump life and
7:43
functioning. It's not a big deal. It's what I would consider a minor advantage
7:49
to the heat exchanger system but this is what this is what you need to do if you
7:56
can't have any exchange of the two sorts of water. So if a system like this
8:02
with a tank style water heater is such a good way to power a hydronic heating
8:07
system how come everyone doesn't use it? Why are there such a thing as boilers
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instead of hot water tanks? Well first of all the tank needs to be up to the job
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It needs to have enough heat output. The tank I've installed at my own place has
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a hundred and fifty thousand BTU per hour input so that's plenty for heating
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needs as well as domestic hot water. Most standard tank style water heaters won't
8:34
produce that much and depending on where you live you can and the size of your
8:38
house and how well it's insulated you can get away with less than that but the
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heater also has to be able to put out heat more consistently. It's going to
8:50
have a far shorter rest period when it's used as a as a space heating
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engine like this is here so you need to have a water heater that's up to the job
9:00
and the manufacturer can tell you that. I mean some companies will not warrant their tank style heaters for this application and others will. The unit
9:09
that I'm using is called the Polaris and it's made by a North American company
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called AO Smith and they specifically build this tank style water heater for
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this application. That's one reason they put on two pairs of taps here. We have
9:29
the cold and the hot for your domestic side and then the
9:34
return and the outflow here on the side of the tank for your hydronic heating
9:40
system. Now another reason you'd want to use a tank style heater is because it's
9:46
just simpler. You've got one appliance and it'll serve you all year round for
9:52
domestic hot water tapping in as needed during the heating season for heating so
9:59
it's it's a simpler system and if you go with the simple installation and you
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eliminate the need for a heat exchanger maintenance is also lower too because
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with any kind of a boiler you've got a built-in heat exchanger of one sort or
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another and that heat exchanger will form scale and things on the domestic
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side of the system so you'll have to flush some vinegar through that heat
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exchanger every so often maybe every six months or a year or two years depending
10:29
on the hardness of the water. You can sidestep that maintenance with a tank
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style heater. The only maintenance that a tank style heater requires is to flush
10:39
any sediment out from the bottom of the tank which is quite an easy thing. You
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flip a valve after you've hooked up a hose to the tank and the sediment
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flushes out. Now if you do have a separate heat exchanger like this you
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are gonna have to do the vinegar treatment and that's why I've installed these these flush valves here. That's something you're gonna want to do so you
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can shut off the flow valve open up these ports here and you can flush some
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vinegar through there with a pump. Usually that only has to happen on the
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domestic side of the system not the hydronic side which doesn't build up
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minerals the same way but as I said you can completely eliminate this
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altogether if you go with a simpler non-exchanger installation. So just to
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recap some of the reasons why you'd want to use a tank style heater. First of all
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they're simple. It's a technology that's been around a long time. It's a
11:42
simple concept and it works well. Another thing is versatility. Any tank style
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heater is going to do a good job for you both space heating and for domestic
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hot water. It's efficient too. The Polaris unit that I've installed has a
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95% efficiency for both legs both the space heating and domestic hot water and
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in some applications it's an especially low maintenance option as well. So there
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you have it
#Heaters
#HVAC & Climate Control
#Plumbing