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[Scott7m]

May I ask you how you think the water is going to keep getting hotter using a plate exchanger?? 

if the water  is in the supply line it cant sit and circulate like it does if you have a sidearm heat exchanger. 

[willieG]

young children can recieve 3rd degree burns in under 4 seconds from hot water that is above 120 degrees F That is almost the time it takes a child to react to the feeling of the water. us old folks dont burn quite so fast but why would you take the chance with your children? i do believe that a lot of new taps in the home have these mixing valves built in but they too can fail, why not have a backup right on yoru tank?

if you use a side arm or a plate exchanger you have the potential of storing water in your hot water tank or even if you are on demand right from your plate exchanger, the possability of your hot water at your tap being 1 or 2 degrees below your OWB temp is very high.  lets say your OWB is at the top of its cycle and you have it set for 180 (factory setting in most cases) if you use a blower fed stove and it reaches 180 and shuts of the air supply and your stove is not drawing heat for your home it is possable for the OWB to climg another few degrees before the gasses burn off or die down from lack of air. so lets say your stove went to 183 now your pump is cycling this 183 water through yoru domestic water heater at this temp because at this time your furnace rad does not need heat, yoru child turns the tap on and then decides to do something like take thier shirt off or anything that may take a few seconds..now while they do this the water is running..when they decide its time to wash thier hands they stick them under the tap and they put them right in to that 180 or better water...ouch! poor kid...put on the mixing valve or turn your OWB down to under 120 and then you likely wont heat your house...PUT ON THE MIXING VALVE i t will also give you a nice steady  stream of "hot enough water"

lets also look at the other  scenerio..you have no mixing valve and you are one of them people who take long long showers.. you start out with  180 degree water so you have the cold turned open a long way to cool it to comfortable...as the OWB temp cools to "kick in temp" your hot water at the tap also cools and you are turning the cold off as you shower to maintain the heat you like..this goes on until your shower is done or if you stay long enough as your OWB recovers you are turning the cold back open to maintain your water temp...a lot of work for a shower....Put in the Mixing Valve  and enjoy trouble free hot water...your wife and kids will love you for it

i guess that was a long winded one...my 15 cents worth..lol

[Scott7m]

You would have to have a line in the bottom of the tank and out the top to make the water start a convection current, like a side arm does.   I have never ever seen a water plate exchanger make the tank water go over what it normally runs, I checked it periodically with a heat gun and it was always the same
within 2-3 degrees

[willieG]

i agree you will not create the syphon effect of a sidearm but if you have a tank full of hot water at say 120 (safe for children)in your domestic tank and you are delivering to that tank 180 from your OWB the temp in the domestic tank has to go up, say it even only goes up 5 or 6 degrees ..the first time the child goes to the bathroom and washes his or her hands the water is safely at 120 the next time they go maybe momma has been doing laundry and she is filling the washer with 15 or 20 gallons of hot water so now your domestic tank just recieved 20 gallons  (possably half of it's capacity) and the water temps is now 125 or even higher remember the last time the child used the tap it was fine, they are not going to test it this time they are just gonna shove their tender skin under there..i  still vote fore safety...mixing valve

again that is only my opinion...i have enough things to worry about besides my grandchildren hurting themselves under my taps...i didn't used to have the mixing valve myself..but i have for the last couple of years.


do i really need it...maybe and maybe not, but it is a safety device and i feel if it was not needed it would have never been offered

[martyinmi]

What if.....
   You do not fully turn off your hot water faucet? If it's leaking a couple gph, what will that do to your tank temperature after you get back from working a 16 hr. double shift? (your boiler temp is 180*)
What if.....
   A hot water faucet develops a leak, or maybe one of your solder joints starts squirting, or a pex clamp decides it's time to start leaking and you do not notice it? The leak amounts to maybe 5 or 10 gph. Where will your tank temperature be after an 8 hour shift?
Now.....
   Lets say your wife's daycare children, or your child, or your elderly parent or grandparent decides to wash up for dinner KNOWING that turning the hot water on only will yield the perfect temperature for hand washing. Your water in your tank is now up to 140* or more. What is going to happen?
   You come across as a very intelligent man. When you do an install, incorporate a mixing valve. If the home owner does not want one, make him sign a waiver to protect yourself from future legal issues.

[Scott7m]

Hey martyinmi, thats a good point.. One I had never thought of, I didnt mean to sound offensive in asking but I sure aint against learning something new.  lol

I see what your saying though, if someone was to leave a faucet barely cracked on hot and it was slowly pulling the water through it could potentially have more time to heat the water and pull in some really hot water into the water tank. 

One thing that amazes me is the different markets..  I can see that the folks in the northern markets really dot there i's so to speak.  Where as people in my market are more after the cheapest way possible to do anything, occassionally you do run across someone here who wants to go the extra mile, but it is rare!  Same way when we start talking efficiency, folks in the north seem really interested, and folks here say oh i got plenty of wood, all i need to know is will it heat my home!   

I agree with your idea about the waiver, I think I should come up with a waiver for safety that covers anything to do with the system actually. 

[martyinmi]

Scott-
   Are you having a harder time selling OWB's now than you did a few years back? Up here, we have lumber companies, hardware stores, etc. selling nearly all the brand name OWB's. They rarely comply with their obligations to the manufacturers, and because they buy in such large quantities, they can sell much cheaper than the small time dealers can. I have a few friends who are dealers, and they say they can see a time in the not too distant future where they won't be able to make anything from the boiler sale, but maybe a little from the install. Some long time dealers are getting turned in because they are not hvac licensed or bonded or both, so they are forced to stop doing installs also. It really makes me wonder what things are coming to when people will drive a few hundred miles to buy an OWB to save a few hundred bucks, knowing full well they won't get any dealer support. I'll bet nearly all the small dealers will be gone up here in 5 years or so and replaced by the large super centers. What do you think?

   Marty 

[Scott7m]

Marty, the only thing I can tell you is that my market is like going back in time 20-30 years compared to
most.  If a "home inspector" or anyone like that tries to tell someone here that he can't do something to his own home, the inspector better be listening for pump action of the ol shotgun, sounds crazy but it's true lol

up north it seems folks and business in general seem strangled by govt regs, here it's just not like that.  It's extremely rural and like I said it's like going back in time, there was a special on dateline a couple years ago about this area, showed people out burning tires and sittin around chugging mt dew as fast as they could open it.  There are areas around here where it's a lot more civilized in the central part of the state, but in the east it's still laid back.

My goals for fighting off the big push is to become a bigger dealer, I'm pushing my advertising budget way up and really getting my name out there to help ward off the scenario you mention.  As this is my only income besides rebuilding a few vehicles a year.   

[oldchenowth]

I applaud any and all of you dealers in today's market.  I am guilty of buying online cheaper than local.  My only excuse is there is no Wood Doctor dealer in Michigan to my knowledge.  For you guys to front the $$$$$ for in stock stoves and the supplies then GIVE away your knowledge to boneheads like me to hook our own up because we watch HGTV and think we can do just as good as a professional, takes a lot of guts. Although my skills are higher than the general public, it just pays sometimes to call in the cat that does this for a living.

Gentlemen (and ladies too), My hat is off to you. 

[Bull]

I second this   /\  /\