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Water temps

16 replies created over 7 years ago
posted by allen over 7 years ago

I am discovering that the original builder of my 6 bay SS car wash was an idiot :(
I have a very nice Lochinvar, very expensive, boiler for making hot water. This unit has to run at 140 degrees return temperature in order to last many years. Settting the T-Stat lower will only hasten the demise of the $4,000.00 heat exchanger. This means that the hot water must be reduced to 120 degrees or less before it hits the car wash system as the manufacturers of several of the items in the system demand no more than 120 degrees. This is commonly done, I have discovered, with a mixxing valve. My car wash has no mixing valve. The idiot spent $500,000.00 building a car wash and forgot the mixxing valve. I have been having problems with the Lochinvar heater and am learning for the first time that this mixxing valve was needed :(
So the question is this. Have any of you any suggestions and or experience with what mixxing valve to use. there are so many of these valves on the
market, it is very confusing :)
Also what temperature do you guys run your systems and do you have mixing valves.
Looking for some experience here guys. The Lochinvar man gets $95.00 an hour to just look haha.
Allen in Wichita


reply by allen over 7 years ago

I just talked to a friend of mine that repairs car wash systems, he says it is common for the water heaters to run at lower than 140 degrees and that he is not aware of mixer valves being needed. Lochinvar states 140 degrees minimum and says a mixer valve is the only way to reduce the temps to lower temps for car wash demands. Would be interesting to hear from others if they have some method other than mixing valves to reduce the temps or are all you just running the boilers at below suggested temps of 140 degrees.

reply by br549 over 7 years ago

For every 17 degrees you raise the temperature of the water soap mixture, you get 100% more cleaning. Your intentions are good but try this. Have your heater up and running and have your high pressure running in the bay. While holding the trigger in the bay place your hand in the spray approximately two feet away from the tip. As the water gets fanned out the heat dissipates into the air. The water that hits your hand is almost cool. The cost of hot water for the results ...... Get your titrations inline for more profit.

reply by allen over 7 years ago

I understand what you are saying br549,but the question is, what is the high temp that a car wash system best runs at. Windtrax wants max of 120 degrees at the equipment ( pumps ) . Boiler companyines want minimu 140 degree at the inlet and with a 19-20 degree rise in te boiler thats 160 degrees.
So if you dont run a mixing valve what are you doing with the temps.

reply by MEP1 over 7 years ago

You need a tempering valve. Search for a Watts Regulator brand that fits the specs you need, get the model number and search online for the best price.

reply by Homer over 7 years ago

John, can you please explain the 17 degree thing? thanks

reply by GregPack over 7 years ago

Yep, 120 degrees is the max I run.

I used to operate a car wash with minimum temp of 140 degrees. That is too warm. The seals in the pump had to be replaced more often and I had a couple of time where the water really got too hot. Plus, you don't want to make heavy de-greasing too easy, or you'll get every Shade tree mechanic coming over for that purpose.

reply by allen over 7 years ago

Started up the Lochinvar after cleaning out the heat exchanger and all went very well BUT I learned one thing. Dont run anything over 120 degree thru Zero pressure regulators,,,it causes steam which causes the pumps to cavitate and all your pumps quit working. Sounds bad to haha.
I was told this would happen above 120 degree but I also was told that my Boiler could be set at 140 intake temp as prescribed by Lockinvar and that with the 19 degree rise in the boiler the 159 degree exit temp would be tempered by cold water injection at the holding tank keeping the hot water down to under 120 as it passed towards the pumps. WELL ya like it didnt.
Try 159 degree water straight to the Zero Pressure regulators.
At least now I know how this system has been abused all these years by running it to low temp. Now I will find a mixing valve and installl it where it wont allow anything hotter than 120 to the system.
I am a little surprised with the responce or lack of responce I got on this question. Its like no body really knows or should I care to say wants to talk about the issue. Boilers need to run at 140 intake to last, but car wash systems are basically restricted to 120 degrees, What is happening is that most I am afraid are just tuning down the temp that the boiler is running at. This is fool hardy, look in your flu and inside you heat exhanger. Your destroying a very expensive piece of equipment.
Now also I dont want to spend the money to run my Lockinvar at 140 but what choice do I have. I will be working on that problem this week.
Lower gas bills or shorter life expectancy of heat exchanger and flus.
I will report :)
thanks and looking forward to any comments or suggestions.

reply by GregPack over 7 years ago

The lack of response is probably from battles you're fighting have been conquered by others.

A boiler is overkill for SSs. I use commercial water heaters. They cost less, are pretty efficient, take up minimal space, have minimal moving parts, and most any jackass can work on them. Simpler is better!

reply by allen over 7 years ago

I wondered about that, any specs available like how big , what capacity,
,,I understand the battles fought thing, its the inventing wheel thing,
But isnt that what this forum is all about. I bet there are lurkers watching this to learn as I fail over and over haha.
And I might point out that I have proven that an idiot can rebuild a Lochinvar Boiler :)

reply by foamycars over 7 years ago


What kind of commercial water heaters do you use instead of using some kind of boiler system? Are you referring to an oversized hot water heater?

reply by GregPack over 7 years ago

Yes, basically a big water heater. It has an automatic damper to slow heat loss. Keep in mind I am in the southern U.S. so my demand may be lower. I used a 199K BTU 100 gallon water heater in 5/1s with no problems. They used to be about 2K. I think they are about 3K now. Never ran out of water and my gas bill was lower than a couple of lower volume sites that had boilers. You can get them up to 400K BTU. I was intrigued by the instant water heaters but you would have to buy two (probably three) for that site and I couldn't can't pencil any savings ROI in a reasonable period. No one around here knew how to work on them, either.

reply by allen over 7 years ago

thanks Greg, I will shop them a bit for info. I think I am stcuck with this big boiler but if I find a better solution and could sell this unit to some one that NEEDS it, who knows. The more I get educated the better I will feel but a good price at a closing would be the best solution hehe.
I am going to put the burden on the Factory as to which is a better financial decision. Run boiler below minimum temps and save money on gas or run at 140 min temp and pay the gas man, you tell me which is the wiser solution over a 10 year period ?????:)
this lochinvar has been running for 10 years at under 120 degree and there was NO buildup in the heat exchanger and no damage to the box, some rust corrosion in the flu but nothing critical.
Again, thanks for the impoot.

reply by blueturtlecarwash over 7 years ago

Whats the deal with the hot water? I have repaired and replaces hundreds of pumps and heating elements for presoak's on IBA's, And by my observations they really don't do anything but waste energy and money on the repairs that will always take place. Maybe I'm missing out on something I didn't see before. I know that a certain chemical in presoaks is temperature sensitive, but other than that, why hot water?

reply by allen over 7 years ago

Blueturtle. Interesting thoughts, Where are you located. In kansas we need hot water for winter operation for sure. People expect to feel the hose get warm while they are washing their cars. As for real purpose. Hot water circulates in the roof with the supply hoses to keep things from freezing, hot water runs thru the soapy brushes in a return line to keep them free of ice. The real need I guess is for freezing and customer satisfaction. ???
In the summer, I turn it off.
I am sure it is a waste soe how but I fail to see how we could do it with out hot water in the winter ????

reply by blueturtlecarwash over 7 years ago

I'm working on changing everything about the Winter time SS experience that is leaps and bounds beyond what we do now. When it is finished I will unveil it. All you northern guys are going to love this one. Its expensive up front but it will be well worth it as far as being "the car wash" to go in town in the winter time. I'm sure I will triple my business. I going to sell it, just because it's that good and because it's going to save and make some serious dollars. Details will be unveiled in summer of 2011. And that all I can say about that. Allen props on falling into the business the way you did. WOW. What a ride.

reply by allen over 7 years ago

Blue turtle, sounds like a indoor water park car wash hehe
good luck. let us know how you do, I hope to be on my boat in the keys by then :)

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