Outdoor Wood Furnace Info

All-Purpose OWF Discussions => Plumbing => Topic started by: mlappin on January 01, 2015, 08:56:53 PM

Title: Maximum temp for appliances
Post by: mlappin on January 01, 2015, 08:56:53 PM
So whats the maximum temp that safe for appliances on the DHW?

I'm redoing the plumbing in the basement this winter, never had a tempering valve before and the wife due to previous health issues can't tell just how hot she has it set. I'm afraid she's actually going to burn herself one of these days, not to mention too hot of water is not good for her blood pressure.

I do know if the water isn't warm enough for the dishwasher it heats it to a set temperature before starting a cycle. Running 180 atm on the old boiler, get it replaced and was planning on 190-195 and was wondering if that additional 10-15 degrees would eb the straw that broke the camels back?

I was thinking of adding one tempering valve for the shower and faucets then maybe a second set higher just for both washers and the dishwasher if required.


Another question, when I buried the Logstor I pulled my one inch pex out of the pipe I made and buried it along wit the Logstor then installed a hydrant by the boiler, was thinking of having either hot or cold water available to it for washing equipment but was wondering if maybe the packings in the hydrant couldn't take hot water?


Title: Re: Maximum temp for appliances
Post by: Jwood on January 01, 2015, 10:49:09 PM
When tap water reaches 140º F, it can cause a third degree (full thickness) burn in just five seconds.
Title: Re: Maximum temp for appliances
Post by: Jwood on January 01, 2015, 10:53:43 PM
Here is a good website for all in relation to hot water and fixtures as well as scalding.
Title: Re: Maximum temp for appliances
Post by: Jwood on January 01, 2015, 10:54:58 PM
Ooops forgot to attach the website  :o
 https://www.energyguide.com/library/EnergyLibraryTopic.asp?bid=tva&prd=10&TID=25821&SubjectID=10182 (https://www.energyguide.com/library/EnergyLibraryTopic.asp?bid=tva&prd=10&TID=25821&SubjectID=10182)
Title: Re: Maximum temp for appliances
Post by: slimjim on January 02, 2015, 03:47:25 AM
Yes mix down your domestic and sending water out to the boiler via a third line is a great Idea, not sure about what the hydrant can take but why not put a plate exchanger in line at the wood boiler, I ran a demonstration at the shows last year with a garden hose to my manifold on the trailer and was getting 165 degrees out of the 50 plate constantly, that will take the grease of the old John Deere!
Title: Re: Maximum temp for appliances
Post by: mlappin on January 02, 2015, 05:49:46 AM
Yes mix down your domestic and sending water out to the boiler via a third line is a great Idea, not sure about what the hydrant can take but why not put a plate exchanger in line at the wood boiler, I ran a demonstration at the shows last year with a garden hose to my manifold on the trailer and was getting 165 degrees out of the 50 plate constantly, that will take the grease of the old John Deere!

Lines already buried to the hydrant, runs into the basement, figured two valves feeding it, the one of the white line (cold) and another from the water heater. I'll have to dig out my power washer manual and see what they claim the seals in the pump can take, I'm betting as well it will be rather low as to prevent the user from getting scalded. I'f I have something really greasy I do have a steam cleaner as well, pressure washer with the higher volume of water is much faster though.

Father's getting remarried and bought another house so we finally get ours back to ourselves, no kids of our own due to the wife cardiac issues so now she's considering the foster care thing, I'm sure they'll do a home inspection and a tempering valve will be a must.

Any thoughts on the appliances though? I know for a fact that the dishwasher has a heating element in the bottom of it to both raise the water temp and to dry the dishes when done, so the internals can take it, but was wondering about the valves and what not.
Title: Re: Maximum temp for appliances
Post by: lmann on January 02, 2015, 07:23:51 AM
Not sure of exact temp for dishwasher but When I start mine I always run the hot water at the sink until I get hot water. The dishwasher doesn't use the heating element for the first half of its cycle. But when it fills for the second half the house water line has gone cold so the first gallons it gets are cold so it now uses the heat element.
So unless you have a recirculating pump for water lines it might not matter if you design hotter to it if your lines are cold to start.
Title: Re: Maximum temp for appliances
Post by: BoilerHouse on January 02, 2015, 07:48:25 PM
Your appliances, valves, piping, packings, seals etc should be able to withstand 200 deg F water.  It is not that hot in the scheme of things.  People, however, should not be exposed to anything this hot.  Like others have said, 140 max. 
Title: Re: Maximum temp for appliances
Post by: LittleJohn on January 05, 2015, 08:11:23 AM
Technically you should be able to run untempered water to any appliance (dish washer or clothes washer), you only have to mix down for faucets, showers and tubs (where humans can put body parts in front of the water stream)
Title: Re: Maximum temp for appliances
Post by: mlappin on January 05, 2015, 09:06:19 AM
Thanks guys. that's what i was looking for. I kinda figured the appliances would handle the higher temps but better safe than a flooded kitchen.
Title: Re: Maximum temp for appliances
Post by: LittleJohn on January 06, 2015, 06:51:03 AM
OK, this is a very dumb possibly stupid question, but you may have to talk with the city or county.  As some jurisdictions have a maximum temperature that can leave a water heater, independent of application.

Now, I doubt your area has this kind of stupid law. 
But I can tell you as a land lord, in the state of MN, I can NOT LEGALLY have water hotter than 125F leave the water heater.   Which is not an issue in the one town house I own, longest run to a fixture is 20'.  I was talking with another land lord, from our management group, had a house with remote bathroom and because of the 125F law, had to put in a secondary point-of-use (instantaneous) DHW in the bathroom
Title: Re: Maximum temp for appliances
Post by: mlappin on January 06, 2015, 08:04:11 AM
OK, this is a very dumb possibly stupid question, but you may have to talk with the city or county.  As some jurisdictions have a maximum temperature that can leave a water heater, independent of application.



Haha, you have obviously mistaken me for somebody that gives a rats ass what the county says.

I'm out in the sticks anyways, nearest city minds their own business and as long as I pay what the county thinks I owe them they don't care either.
Title: Re: Maximum temp for appliances
Post by: juddspaintballs on January 06, 2015, 08:19:34 AM
I'd temper just faucets and run full heat water to the dish washer and washing machine. 
Title: Re: Maximum temp for appliances
Post by: LittleJohn on January 06, 2015, 10:18:25 AM
OK, this is a very dumb possibly stupid question, but you may have to talk with the city or county.  As some jurisdictions have a maximum temperature that can leave a water heater, independent of application.
Haha, you have obviously mistaken me for somebody that gives a rats ass what the county says.
I'm out in the sticks anyways, nearest city minds their own business and as long as I pay what the county thinks I owe them they don't care either.

Kinda of figured, location was AWAY from the city, but had to throw that little bit of knowledge at ya.
Title: Re: Maximum temp for appliances
Post by: mlappin on January 06, 2015, 08:38:57 PM
Couldn't he have installed a tempering valve at the water heater, turned the heat up then installed a second tempering valve at the remote bathroom? Or was it just taking way too long to get any hot water to it?
Title: Re: Maximum temp for appliances
Post by: LittleJohn on January 08, 2015, 07:13:10 AM
Couldn't he have installed a tempering valve at the water heater, turned the heat up then installed a second tempering valve at the remote bathroom? Or was it just taking way too long to get any hot water to it?
MLAPPIN, if you are talking to me

..in Minnesota, reidential rental properties can not have DHW set above 125F, and yes his run from DHW to remote bathroom was like 80-100' when including rise and run, etc.  Water would get to faucet and be luke warm at best, and it could easily take upwards of 5 minutes plus to get "shower-quality" heat out of the water.  For the guy it was cheaper to install and run the small secondary Point-of-use water heater, than any of his other options to keep tenants happy