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Boiler Replacement Options - Win a $25 Restuarant Card!

Randy said:
I don’t understand why you guy’s keep fighting with these gravity fed tanks. The simplest solution is to put a Generant regulator on the water inlet, a DEMA injector and feed the pump with reduced city water pressure, Hot and Cold. They aren’t a big maintenance item, in 32 years I think I’ve replaced 3 or 4 regulators, never touched the injectors. No more Float valves, no more over flowing tanks, no check valves, I’ve never had a washed out Cat 310 pump head. The pumps run quieter because they aren’t working as hard to draw suction.
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Randy,
You might have already told me, but how are you switching between hot and cold water?
 
MEP001 said:
You don't need a regulator for the cold water rinse.

I still think your best long-term option is to go with a high-efficiency on-demand heater and eliminate both the boiler and tank. What would you save by cutting your gas bill down by 20%?
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If I were to direct plumb the hot to the pump eliminating the gravity feed, would I need a regulator so soap would continue to draw through it's existing solenoid?


My gas bill in the winter can be as high as $400. Saving $80 a month in the winter would be nice, but what I really want is a system that is reliable and simple to operate/maintain.
 
Potential Solution needs serious review!

I've attached a diagram of a potential solutions. I have no idea if it will work, but that's what I'm hoping to find out.

Make the current holding tanks for cold water rinse supplied by city water.

Use a Navien tankless heater that will not cut flow rates down even if the desired temperature has not been met. Supply the hot water directly to the pumps as is seen in the diagram.

Potential problems: The Navien will produce hot water as low as .5 gmp. Would this be okay with a regulator and only one pump running?

Would high pressure soap still flow into the line?

If I eliminate the regulator, is there a better way to feed the chemical- injectors perhaps?
 
RockyMountain said:
If I were to direct plumb the hot to the pump eliminating the gravity feed, would I need a regulator so soap would continue to draw through it's existing solenoid?
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You would need a zero-pressure regulator for each pump, unless you can find a line regulator that can do the same thing.
 
RockyMountain said:
I've attached a diagram of a potential solutions. I have no idea if it will work, but that's what I'm hoping to find out.
Click to expand...

It doesn't make sense to eliminate the hot water gravity tank just to have a cold water one instead. It would be a lot simpler and less expensive to leave the hot water side alone and just add a rinse solenoid and a check valve.
 
RockyMountain said:
So do you connect the chemical line directly to the zero-pressure regulator like this one from KR?
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Yes, it has two inlet ports for soap and wax. It has to go after the solenoid for the hot water or there's no point in using the regulator. It actually brings the water pressure to zero psi just like what comes from the tank.

One point if you use them: the bypass from the regulator needs to tee back in before the regulator. They work well but they don't react quickly enough to the change in flow when the trigger is pulled/released.
 
MEP001 said:
It doesn't make sense to eliminate the hot water gravity tank just to have a cold water one instead. It would be a lot simpler and less expensive to leave the hot water side alone and just add a rinse solenoid and a check valve.
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Well, I've put a lot of thought into that one. Here is the reasoning:
1- our holding tanks often cool off leaving a fair number of customers with cold water and certainly every early morning customer.

2- I already have the wiring done with the soap solenoid so I will simply wire them together. When the soap solenoid opens, so does the hot water solenoid. I would not have to run new wires for a cold rinse solenoid which to me simplifies things a lot.
 
MEP001 said:
Yes, it has two inlet ports for soap and wax. It has to go after the solenoid for the hot water or there's no point in using the regulator. It actually brings the water pressure to zero psi just like what comes from the tank.
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Okay, unfortunately I was counting on pressure in that line to enter the pumps over the gravity fed cold water. So that wouldn't work unless I was able to shut off the cold water.

How about this option: Continue to use the gravity tanks for hot water. Since the only chemical that will be going out with the hot water is high pressure soap, couldn't I eliminate that solenoid and directly connect the soap? Could that work?

I could then re-wire that solenoid to activate when "rinse" was selected and move it to the cold water side eliminating the need to run wires.
__________________
Or directly feed the hot water and come up with a new way to inject the soap.
 
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RockyMountain said:
Or directly feed the hot water and come up with a new way to inject the soap.
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I have no idea if this will work, but I've thought about using a Dosatron injection pump which is powered by the water pressure and have that pump the wax in with the cold water rinse. From what I've read, the Dosatron reduces the pressure by about 5%, so a regulator on both hot water and Dosatron supply would be needed to keep the pressures the same. I'd experiment with it if the pumps weren't so expensive.

Have you thought about using an on-demand heater as a recirculating heater for your gravity-feed holding tank? It would solve the problem of early-morning customers getting cold soap. I helped someone with an old wash that had a boiler heating the water in the tank with a pump that ran all the time, and we put a programmable relay on it to let the pump run only when a bay was on.
 
MEP001 said:
It doesn't make sense to eliminate the hot water gravity tank just to have a cold water one instead. It would be a lot simpler and less expensive to leave the hot water side alone and just add a rinse solenoid and a check valve.
Click to expand...

I agree....This method will not interupt the current way you vacumm feed soap. If you change to city pressure Hot Water to the pump, you'll have to come up with another way of injecting soap.


I also agree with Mep about adding a small demand heater to circulate water in the float tank. I had the same concerns.
 
2Biz said:
I agree....This method will not interupt the current way you vacumm feed soap. If you change to city pressure Hot Water to the pump, you'll have to come up with another way of injecting soap.
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Yes this makes good sense. Here is a picture of the diagram for this plan.

Can I directly feed the soap into this line without a solenoid? This hot water supply line will only be used for high pressure soap as we don't offer high pressure wax.

I would like to use that solenoid and re-wire it for the cold water rinse supply.
 
2Biz said:
I also agree with Mep about adding a small demand heater to circulate water in the float tank. I had the same concerns.
Click to expand...

The Navien offers a circulation input. Should I somehow try to use that?

Do you have an example of a small demand heater? Is it something I can buy from kleene-rite?

Thanks!
 
If you're not going the condensing tank route, then by all means, use the built in circulator of the Navien to keep your float tank heated. I believe this is a seprerate line in -out from the demand heater. Down load the manual from Naviens website to verify

I see what you are tryig to do with the diagram, but I would still want a solenoid shutting off the soap. Basically have a solenoid between your soap tank and hot water supply, between the CV and HW float tank. Otherwise you have two tanks trying to seek level! This could present a problem.
 
2Biz said:
If you're not going the condensing tank route, then by all means, use the built in circulator of the Navien to keep your float tank heated. I believe this is a seprerate line in -out from the demand heater. Down load the manual from Naviens website to verify

I see what you are tryig to do with the diagram, but I would still want a solenoid shutting off the soap. Basically have a solenoid between your soap tank and hot water supply, between the CV and HW float tank. Otherwise you have two tanks trying to seek level! This could present a problem.
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Good info thanks!

1- Would I need a temperature controlled circulating pump on the line from the tank to the heater?

2- That's a great point about the 2 tanks trying to seek level. The soap tank is well below the gravity tanks, so that's an issue. Is there any kind of low pressure check valve that would work?

3- How difficult is it to run wires to add a rinse solenoid?
 
RockyMountain said:
1- Would I need a temperature controlled circulating pump on the line from the tank to the heater?
Click to expand...

I think I read somewhere that the circ pump on the Navien monitors line temp and kicks on from an internal timer. This is the fun of researching and designing your own system. You create the need then learn how to fill it! D/L the manual of the navien and see if it will do what you want. Otherwise you'll need a circ pump and T-Stat (Well Stat) to control the circ pump.

RockyMountain said:
2- That's a great point about the 2 tanks trying to seek level. The soap tank is well below the gravity tanks, so that's an issue. Is there any kind of low pressure check valve that would work?
Click to expand...

I would put in a solenoid valve...

RockyMountain said:
3- How difficult is it to run wires to add a rinse solenoid?
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What kind of bay rotary switch do you have? Surely you can pick up a 24v source from the control panel when the rotary switch is calling for cold water rinse.
 
2Biz said:
What kind of bay rotary switch do you have? Surely you can pick up a 24v source from the control panel when the rotary switch is calling for cold water rinse.
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A solenoid valve definitely looks like the way to go.

We are using a shallco 8 position-2 stack. Yes, will have a 24 volt somewhere... Although the exterior of our wash has been renovated, the equipment room is still 30 years old and the wiring is a challenge! Unfortunately, there is not set "control board." Thankfully the car wash company that installed our automatic is going to tackle this one for me.
 
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