Tankless Water Heater & Mash Temp

[Randar]

That is a bummer that you can only go up in increments of 10. Looks like the guy did a very nice install. Good idea with the divert valve. I guess this is out of the question for replacing a HLT. Too bad....

Not really, but the time you need to be using/heating the HLT is dramatically reduced. No inefficient propane usage or expensive electricity rates to bring
water up to mash or sparge temps.

 

[cruelkix]

Not really, but the time you need to be using/heating the HLT is dramatically reduced. No inefficient propane usage or expensive electricity rates to bring
water up to mash or sparge temps.

Yeah I mean i use my hot water heater to give me 120 degree water right now and it totally helps for both strike and sparge water. But yeah, looks like I can't get rid of the HLT all together unless I rig it up.

 

[wildwest450]

Obtrusive? Compared to a 75 gallon hot water heater the thing is tiny.

True, but my hotwater heater doesn't have 15 rows of lines running all over the place.

Don't get me wrong, I like the idea.

 

[Randar]

True, but my hotwater heater doesn't have 15 rows of lines running all over the place.

It only has gas and water in/out (and venting/intake which for most folks is tied to a flue in their traditional hot water heater setup). These are direct vent like high efficiency furnaces.

 

[cruelkix]

True, but my hotwater heater doesn't have 15 rows of lines running all over the place.

Don't get me wrong, I like the idea.

Like Randar said, it has the same number of in/outs as your current heater does except he has some extra piping and stuff to run it to his brew rig. I hear what youare saying tho, it looks like more, but I think thats becuase on a standard water heater, the take up vertical space more than wall space.

 

[Jknapp]

I also have a diverter valve, but I still have to remember to go hit the keypad back to normal temps.

So true. I have to do remember to do the same. I forgot to change it the other day.. luckily the wifey & little one were napping and i remembered..

Next addition: a "change it back to 120 dummy" sign to hang on the diverter valve..

 

[Beernip]

I also have a diverter valve, but I still have to remember to go hit the keypad back to normal temps.

That's a good idea. I sometimes get in trouble from the mrs when I forget to change it back. I get in more trouble when she hops in the shower after I have it set at 90* for filling a carboy with hot water than for having it at my 140* max but at 180* that could cause some hurt.

You could also take a que from Brewmasters where they have the hot and cold line run in to a Y joint out with valves on each side. Keep the hot side at 180 and add enough cold water to bring the temp down to close to the correct temp. He keeps and eye on the thermometer while he is filling and adjusts the cold as needed.

 

[Melnyk]

a little o/t but im a plumber by trade, did he install any valves to flush out the heat exchanger of the heater? usually you have to flush out these things with vinegar every so often to kill the scale on the inside of the HE when they get scaled up they will throw an error code...

 

[Jknapp]

I have been able to hit 180 with 45 degree ground water. Flow rate is ???? as I have not measured exactly.

I wouldn't trust the hot water heater to hit the EXACT temp you need for mash-in though... I would still have some kind of regulating tank.

You have the Noritz right? Hold up & down arrow (on keypad) at the same time and you enter a list of service codes. Scroll with up arrow to 31 & it will tell you precisely the outgoing GPM's. It can tell you a bunch of other cool things too. I'll get the list and post what the codes are..

It can tell you the exact temp of the water leaving the hot water out. When I set my temp to 180 and ran it, there are moments when the heater has heated the water to 195+ - for brief moments, then it settles back to 180 on the nose.

 

[Randar]

a little o/t but im a plumber by trade, did he install any valves to flush out the heat exchanger of the heater? usually you have to flush out these things with vinegar every so often to kill the scale on the inside of the HE when they get scaled up they will throw an error code...

Mine has output valves right below the tank that I could use to backflush or the like as you note, but I have very very low mineral content water here with Lake Michigan water. I actually threw on QD's so I take my brewing water from as near the source as possible (and with the disconnect for the rest of the house engaged)

I don't see the same in the pictures above, but they could be hidden?

 

[Randar]

You have the Noritz right? Hold up & down arrow (on keypad) at the same time and you enter a list of service codes. Scroll with up arrow to 31 & it will tell you precisely the outgoing GPM's. It can tell you a bunch of other cool things too. I'll get the list and post what the codes are..

It can tell you the exact temp of the water leaving the hot water out. When I set my temp to 180 and ran it, there are moments when the heater has heated the water to 195+ - for brief moments, then it settles back to 180 on the nose.

Cool! I never bothered reading the manual...

 

[Jknapp]

What does one of these run, ballpark? And is it as obtrusive as it looks in the pic?

Awesome potential for homebrewers.

Its roughly 9"D x 28"H x 20"W - without the plumbing of course. It takes up considerably less space than my old 50 gal water tank. The new tankless take up a few square feet, while the old tank took up cubic vertical feet.

My pal is a plumber so he cut me a great deal & I assisted with the install. These units are around $1500, without installation. In a typical situation that would probably add another 1,000-1,500.

Pricey yes, BUT, my local gas co is offering a $200 cash rebate for these units. The Govt ran a 30% of invoice tax rebate until Dec 31 2010, which is approx $800 for me. My old water tank is nearing the end of life at 6 years old & that would have cost me $700-900 for an install. So it started to get cost effective & logical when I realized the brewing potential.

Plus, these units have a 20+ year lifespan.

 

[Jknapp]

That is a bummer that you can only go up in increments of 10. Looks like the guy did a very nice install. Good idea with the divert valve. I guess this is out of the question for replacing a HLT. Too bad....QUOTE]

But really, by the time i'm pouring 180 degree water into my cold mash tun (cooler) and it preheats for a few minutes, I'm guessing I'll be right around my 12-14 degree above mash-in target temp. Or if not, a couple splashes of cold water should do the trick.

This also means instant mash-out & sparge water. Yes - the HLT, for me, is dead.

 

[Jknapp]

a little o/t but im a plumber by trade, did he install any valves to flush out the heat exchanger of the heater? usually you have to flush out these things with vinegar every so often to kill the scale on the inside of the HE when they get scaled up they will throw an error code...

Yeah, he installed an isolator valve kit for this purpose. Although, our water is so soft here, there isn't hardly any scale issue.

 

[Montanaandy]

Just got it put in last week. No problem hitting 180 degees with a flow rate of 2.4 GPM. My ground water temp is 47 degrees. I only brew 5-6 gal batches, so I can collect my mash & sparge water in a few minutes.

One bummer: if you turn the heater up past 140, you can only set the temp in 10 degree increments, so 140, 150, 160, etc up to 180. I thought I'd be able to precisely set the temp desired, so that was a bit of a let-down.

here's a few pics..

For a brew op of that size (55 gal), I think you would need several tankless heaters in series. But it would be totally doable. Or, just use one and have a well-insulated liquor tank. My plumber who installed mine, said he uses his to fill his hot tub.

I'll brew my 1st batch on it this weekend. I'm interested to find out how the unit affects my brew day.

I have had a Navien direct vent TWH for a couple of years. My setup does not resemble yours (I run double-walled copper in and as I direct vent out from the basement to the outside above).

Interesting idea about using this to pre-heat your water prior to the boil. How many BTU's are you using to get the water from 45' to 180 to 220' via the TWH versus taking 120' water and getting it up to 220' (+100') on the stove? Are you using natural gas or propane (I use propane). Montanaandy

 

[Montanaandy]

Plus, these units have a 20+ year lifespan.[/QUOTE]

Not if you are running them that high they won't (assuming you have a recirc pump involved in your system). Montanaandy

 

[Jknapp]

I have had a Navien direct vent TWH for a couple of years. My setup does not resemble yours (I run double-walled copper in and as I direct vent out from the basement to the outside above).

Interesting idea about using this to pre-heat your water prior to the boil. How many BTU's are you using to get the water from 45' to 180 to 220' via the TWH versus taking 120' water and getting it up to 220' (+100') on the stove? Are you using natural gas or propane (I use propane). Montanaandy

Its a 199,000 BTU Nat Gas unit, so I would assume that when I run it at 180 degrees, its using close to all of that. All built-in efficiency of the unit is out the window when running it wide open I'm sure. Its probably eating gas like a monster.

After run off, I boil with electric. No BTU's there.

 

[wildwest450]

IThese units are around $1500, without installation. In a typical situation that would probably add another 1,000-1,500.

Pricey yes, BUT, my local gas co is offering a $200 cash rebate for these units. The Govt ran a 30% of invoice tax rebate until Dec 31 2010, which is approx $800 for me.

Not bad considering I just paid $500 for a 50 gallon gas heater, my old one lasted a whopping 5 years. Plus nat gas here is dropping like a rock, hmmm...

 

[Randar]

Plus, these units have a 20+ year lifespan.

Not if you are running them that high they won't (assuming you have a recirc pump involved in your system). Montanaandy

My parents have 2 Bosch tankless heaters that are 22 years old and have been running at 140 degree output for that entire time in a house of 5 people for more than half that time. A few minor part replacements is it and this is "older" technology.

Nobody here is suggesting running at 180 all the time, BTW, and yes, they last longer than that without issue, generally, as long as your water doesn't have high mineral content. If it does, it just takes a more regular maintenance cycle to ensure there isn't too much build-up.

 

[Randar]

I have had a Navien direct vent TWH for a couple of years. My setup does not resemble yours (I run double-walled copper in and as I direct vent out from the basement to the outside above).

Interesting idea about using this to pre-heat your water prior to the boil. How many BTU's are you using to get the water from 45' to 180 to 220' via the TWH versus taking 120' water and getting it up to 220' (+100') on the stove? Are you using natural gas or propane (I use propane). Montanaandy

first of all, i have to use propane to heat the water if I don't use the tankless, so the "per BTU" cost of propane tanks is many times that of NG for me. Yeah, I could tap into my NG and will eventually, but for now the cost difference is significant.

Secondly, the Noritz is generally rated ~83% efficient. Meanwhile, a traditional electric stove element is ~70% and open flame NG is less than 60% IIRC and I am sure even less than that the way we use it with big flames, outside, and larger vertical columns of water (heat loss through walls and open surface of water with evaporation)...

I don't think I would be overstating that it would be a dramatic reduction in actual gas usage to get the water to that temp even running "full out". I haven't done the math but I doubt the difference in efficiency between heating 7 gpm @75 degree temp rise (all of these higher end units rated comfortably for a similar gpm flow) and 135 degree temp rise at 2.5 gpm, I don't think you're going from 83% efficiency to something silly like 60% (which would be the required drop to even bring this usage scenario's efficiency into question)

 

[Bensiff]

I had the Navien Condensing unit installed at 98% efficiency, given the efficiency of a open propane burner the tankless route is sure to save money on brewing.

JKnapp, I'm still stuck on the water filtration issue. Since I live in the area we have pretty much the same water supply so I would be interested to hear what your results are without filtering the water. I want this to work for me, but can't get over the spector of chloro-phenols.

 

[Jknapp]

Cool! I never bothered reading the manual...

These service codes aren't in the manual.. I was wrong about the code (#31) I gave you earlier. I'll get the list today and post it.

 

[Jknapp]

first of all, i have to use propane to heat the water if I don't use the tankless, so the "per BTU" cost of propane tanks is many times that of NG for me. Yeah, I could tap into my NG and will eventually, but for now the cost difference is significant.

Secondly, the Noritz is generally rated ~83% efficient. Meanwhile, a traditional electric stove element is ~70% and open flame NG is less than 60% IIRC and I am sure even less than that the way we use it with big flames, outside, and larger vertical columns of water (heat loss through walls and open surface of water with evaporation)...

I don't think I would be overstating that it would be a dramatic reduction in actual gas usage to get the water to that temp even running "full out". I haven't done the math but I doubt the difference in efficiency between heating 7 gpm @75 degree temp rise (all of these higher end units rated comfortably for a similar gpm flow) and 135 degree temp rise at 2.5 gpm, I don't think you're going from 83% efficiency to something silly like 60% (which would be the required drop to even bring this usage scenario's efficiency into question)

I'll find out for us Randar. One of the service codes tells you the percent efficient while the unit is in running. Brilliant technology I tell ya.

 

[Jknapp]

I had the Navien Condensing unit installed at 98% efficiency, given the efficiency of a open propane burner the tankless route is sure to save money on brewing.

JKnapp, I'm still stuck on the water filtration issue. Since I live in the area we have pretty much the same water supply so I would be interested to hear what your results are without filtering the water. I want this to work for me, but can't get over the spector of chloro-phenols.

I'll let you know, but for the record, I never filtered any of my water before. In previous batches, I never used hot water from my tank water heater to avoid potential sediment, etc - I only used from the cold line. So.. the only difference with the tankless is the cold water is super-heated before I get working with it. I can't think it'll be much different. I guess all my previous batches had chloro-phenols in them and they tasted pretty good!

 

[Randar]

I had the Navien Condensing unit installed at 98% efficiency, given the efficiency of a open propane burner the tankless route is sure to save money on brewing.

Just checked out those models. Holy-moly. More like a 2-stage furnace than previous tankless models. A lot of "newer" technology in there but much more efficient. My folks are building their retirement home "green" so this looks perfect for them. I had never heard of them so they must be relatively newer on the market since last I looked in detail was ~4 years ago.

 

[Randar]

I'll find out for us Randar. One of the service codes tells you the percent efficient while the unit is in running. Brilliant technology I tell ya.

I meant to ask you as well, when you measured 2.4 gpm at 180, was that out of the 3/4" valve or through a fixture that might restrict flow. 2.4 gpm sounds a lot like a possible laundry sink flow rate (w/o a flow restrictor). I did notice some "pulsing" in the flow when I have the valve wide open and temp set to 180. It must have been dialing back the flow to allow the heater to keep up, but I was connected right to the 3/4" valve with a 5/8" ID hose, so there were really next to zero restriction on the flow rate I was requesting.

 

[Bensiff]

Just checked out those models. Holy-moly. More like a 2-stage furnace than previous tankless models. A lot of "newer" technology in there but much more efficient. My folks are building their retirement home "green" so this looks perfect for them. I had never heard of them so they must be relatively newer on the market since last I looked in detail was ~4 years ago.

Yeah, its an impressive unit, supposed to handle 4 showers at the same time...of course I only have two. Sounds like a jet firing up when it goes full bore, but other than that I'm digging it...supposed to be really reliable too. I think the only downfall with these things is that there is more lag time to get hot water than a tank as it has to fire up and start heating, but they do make some sort of small tank system to help with that I believe.

 

[Bensiff]

I'll let you know, but for the record, I never filtered any of my water before. In previous batches, I never used hot water from my tank water heater to avoid potential sediment, etc - I only used from the cold line. So.. the only difference with the tankless is the cold water is super-heated before I get working with it. I can't think it'll be much different. I guess all my previous batches had chloro-phenols in them and they tasted pretty good!

Yup, this is gonna bug me, the thought of the time and money savings of shorter brew days and fewer trips to fill propane is ringing in my head. I'm going to have to do a batch with tap water now to see if it causes flavor problems, I've been filtering for so long I can't remember if it made a difference with our Seattle water.

 

[Randar]

Yeah, its an impressive unit, supposed to handle 4 showers at the same time...of course I only have two. Sounds like a jet firing up when it goes full bore, but other than that I'm digging it...supposed to be really reliable too. I think the only downfall with these things is that there is more lag time to get hot water than a tank as it has to fire up and start heating, but they do make some sort of small tank system to help with that I believe.

Yeah, the recirculating option (it actually does the recirculation internally with a far-side hot water return inlet and small buffer tank) seems to be a more tightly coupled option than others I have seen.

But if you are simply comparing to a tank? First of all, you can put a tankless in a much more confined space so you can locate it more centrally (to reduce the longest run) if you wish to do so. Secondly, even if you're simply replacing the current tank, we measured only a 4-5 second increase in "time to hot" at our furthest run.

Mine can be loud running full bore as well. Definitely not silent, but it's int he basement next to the furnace (which also is not silent) so you can insulate the area for sound if you care about that sort of thing.

 

[Jknapp]

I meant to ask you as well, when you measured 2.4 gpm at 180, was that out of the 3/4" valve or through a fixture that might restrict flow. 2.4 gpm sounds a lot like a possible laundry sink flow rate (w/o a flow restrictor). I did notice some "pulsing" in the flow when I have the valve wide open and temp set to 180. It must have been dialing back the flow to allow the heater to keep up, but I was connected right to the 3/4" valve with a 5/8" ID hose, so there were really next to zero restriction on the flow rate I was requesting.

The 2.4 gal reading was from the unit service code for GPM output, while it was putting out 180 degree water.. The hot line comes out of the unit to 3/4" copper, runs about 10 feet, then reduces to a 1/2" stainless valve/barb. Its an UNrestricted output.

So, the tankless was giving me that reading. As the unit cranked up to 180, the volume/pressure significantly reduced from around 8 GPM to 2.4 GPM. If you tell it you want 180 degree water, the flow reducer adjusts output.