Boiler Replacement Options - Win a $25 Restuarant Card!

[2Biz]

Now, After you’ve had time to digest all that, I’ve offered you two options. If you settle on a Demand heater and keeping you holding tank, Your looking at about $3,000 for the install…
$1500 for 199K BTU Condensing Demand Heater
$600 for Taco 2400-50S S.S Circulation Pump
Another $900 for T-stat, 1” copper tubing, wiring, relay for pump, box for relay, intake and exhaust venting, service ports (To clean boiler scale) shut-off flanges for pump, etc., etc.
Plus time to do the install?

OR

I’m wondering if you looked at my other suggestion? Post 16? You can also compare the link in this post to a Polaris PGC3 50-199-3NV which is another tank style water heater, It has a recovery rate of 426 gph @ 60° temperature rise. These two units are condensing tank style heaters (High efficiency) that have almost “NO” head pressure through the heater. You would simply replace your existing holding tank and forgo all the extra plumbing, pumps, relays, and wiring…You simply hook it up to city water. For about a $1000 more… How much is your time worth? If I were to replace my (not working 350K Jarco Boiler) I would seriously consider one of these or similar….

 

[MEP001]

So is there a resource anyone knows of that can provide a diagram that includes the location of the pump/ pressure relief valves/ gages/ and heater for my situation, as well as recommendations on pump sizing based on the heater chosen? Do individual water heater companies provide this?

As far as pressure relief valves, you should already have one in the tank and there's a place for one in the heater, so that's covered. I don't know that you'd need a gauge, but if you want one the best place IMO would be on the outlet of the tank or on the plumbing to the inlet of the heater. You could start out with your existing pump left in place and replace it if it's not big enough. I don't see that you'd need to worry much about head/lift with a closed-loop recirculating system like this since the only thing providing any resistance to flow would be the heater itself. 2Biz is having to pull/push water through many feet of floor heat tubing, which is why he had problems with one pump.

 

[MEP001]

I’m wondering if you looked at my other suggestion? Post 16? You can also compare the link in this post to a Polaris PGC3 50-199-3NV which is another tank style water heater, It has a recovery rate of 426 gph @ 60° temperature rise. These two units are condensing tank style heaters (High efficiency) that have almost “NO” head pressure through the heater. You would simply replace your existing holding tank and forgo all the extra plumbing, pumps, relays, and wiring…You simply hook it up to city water. For about a $1000 more… How much is your time worth? If I were to replace my (not working 350K Jarco Boiler) I would seriously consider one of these or similar….

I'd probably go that route too. Those insulated tanks are around $1500 and they don't last forever.

 

[RockyMountain]

I'd probably go that route too. Those insulated tanks are around $1500 and they don't last forever.

I've definitely looked at post 16, and it may very well be the way to go. I'm meeting with a couple local mechanical companies today and tomorrow, so it will be interesting to see if they provide this as one of the options they would go with. I'll let you know.

 

[RockyMountain]

I’m wondering if you looked at my other suggestion? Post 16? You can also compare the link in this post to a Polaris PGC3 50-199-3NV which is another tank style water heater, It has a recovery rate of 426 gph @ 60° temperature rise. These two units are condensing tank style heaters (High efficiency) that have almost “NO” head pressure through the heater. You would simply replace your existing holding tank and forgo all the extra plumbing, pumps, relays, and wiring…You simply hook it up to city water. For about a $1000 more… How much is your time worth? If I were to replace my (not working 350K Jarco Boiler) I would seriously consider one of these or similar….

Definitely something to consider. Have you decided if you are going to pull the trigger and go with hot water?

 

[RockyMountain]

As far as pressure relief valves, you should already have one in the tank and there's a place for one in the heater, so that's covered. I don't know that you'd need a gauge, but if you want one the best place IMO would be on the outlet of the tank or on the plumbing to the inlet of the heater. You could start out with your existing pump left in place and replace it if it's not big enough. I don't see that you'd need to worry much about head/lift with a closed-loop recirculating system like this since the only thing providing any resistance to flow would be the heater itself. 2Biz is having to pull/push water through many feet of floor heat tubing, which is why he had problems with one pump.

My current pump is not a type that would work, as it is attached directly to the side of the boiler.

I may be wrong, but isn't a closed loop system like a floor heat system? City water enters the holding tank and then I would be pushing it through the heater and then back to the holding tank. This would still be considered an open loop, since water flows in and out... correct?

 

[2Biz]

As far as pressure relief valves, you should already have one in the tank and there's a place for one in the heater, so that's covered. I don't know that you'd need a gauge, but if you want one the best place IMO would be on the outlet of the tank or on the plumbing to the inlet of the heater. You could start out with your existing pump left in place and replace it if it's not big enough. I don't see that you'd need to worry much about head/lift with a closed-loop recirculating system like this since the only thing providing any resistance to flow would be the heater itself. 2Biz is having to pull/push water through many feet of floor heat tubing, which is why he had problems with one pump.

Mep, I didn't have a problem with the pump supplying my zones, just the pump supplying pressure to the Takagi. You have to make sure you have a pump capible of 50ft of head pressure @ 10 gpm of flow when using a demand heater. His current "Boiler" is full flow with no restrictions in the boiler, like my old Jarco 350K boiler. It had 1-1/4 heavy wall copper all the way thru the boiler. No restrictions like the Demand heaters. I'm guessing his current pump (If there is one) is not big enough.

 

[2Biz]

My current pump is not a type that would work, as it is attached directly to the side of the boiler.

I may be wrong, but isn't a closed loop system like a floor heat system? City water enters the holding tank and then I would be pushing it through the heater and then back to the holding tank. This would still be considered an open loop, since water flows in and out... correct?

Your right to a degree. But in a floor heat system, a closed loop system means it can be pressurized and it also means there is no oxygen in the system. Or thats what you try to achieve anyway. Oxygen is what allows any metal parts to corrode. You have to use a S.S. pump or Bronze pump in an open floor heat system. An open system is vented to outside air. But there are many other benifits to having a closed loop system. Why do you ask?

If I were to add hot water to my current setup, I'd have to make major changes/modifications. My mix tanks (6 compartment, hot, cold water, wax, soap, FB, and Presoak) are old and I don't know how much life it has left. It is S.S., but everything has its limits. So I need to let this wash make some $$$ before sinking more into it. It is doing better, but not enough to justify another $5-$6 grand at this time...

 

[RockyMountain]

Your right to a degree. But in a floor heat system, a closed loop system means it can be pressurized and it also means there is no oxygen in the system. Or thats what you try to achieve anyway. Oxygen is what allows any metal parts to corrode. You have to use a S.S. pump or Bronze pump in an open floor heat system. An open system is vented to outside air. But there are many other benifits to having a closed loop system. Why do you ask?

I asked because Mep001 said I would have a closed loop system. I was trying to clarify that it wouldn't be closed loop because new city water (with oxygen) would be circulating through the system. In my mind, closed loop is like a floor heat system or a closed boiler that is using a heat exchanger, meaning the city water never goes through the boiler. Am I wrong?

 

[RockyMountain]

Changing from gravity fed...

Okay- a new thought. I gravity feed the pumps meaning hot water for high pressure soap and high pressure rinse (no high pressure wax). What would be involved in trying to switch over to a system that only has hot water for soap and cold water for high pressure rinse. Seems like it might reduce the demand for hot water by almost half, meaning a smaller unit would do.

 

[mjwalsh]

I removed my 600k btu (I think) 82% efficient ( when new) boil and tank with recirculating pump with an Eternal mounted up on the wall. Very efficient (95% i think) and no maintenance. It keeps up with my 3 self serv and 1 automatic (presoak only). I set at 110 degrees, if it cant make 110 it lets water through ( so no starving pumps).

Turbo
Chicago

RockyMountain,

I put the above quote because I believe if I understand Turbo correctly he did away with both his boiler & his tank. It seems like he just has a Tankless to serve 3 bays plus the presoak of his Automatic. Based on that ... you could get by & not have to continue to maintain the pressurized tanks & the circulating pump. That is assuming that your city water pressure is above 40 PSI & preferably closer to 60 PSI when full demand occurs. This is also assuming that you have small float tanks on each pump.

If you can keep your existing setup in place ... while you are setting up the new system up you can 100% verify that the tankless by itself won't starve the float tanks & the temps are within your acceptable consistent range.

We were fortunate enough to have a mechanical engineer friend who helped us with redoing our tempering valve setup over 25 years ago. On the inlet side of the stainless steel Symmons Tempering Valve he spec'd out a recirculating line that kept the tempering valve extra accurate. If & only if in that event of an unexpected starving situation ... you could put a tempering valve after the tankless & even if the GPM went down because of the Tankless you would still have enough GPM. It seems like you could then set the output temperature of the tankless (less flow) much higher with the tempering valve. I mentioned the accuracy of the tempering valve is because it seems like that the Navien "A" series' small buffer tank with the tiny built in circulator could do something similar to what the mechanical engineers design did.

mike

 

[MEP001]

Okay- a new thought. I gravity feed the pumps meaning hot water for high pressure soap and high pressure rinse (no high pressure wax). What would be involved in trying to switch over to a system that only has hot water for soap and cold water for high pressure rinse. Seems like it might reduce the demand for hot water by almost half, meaning a smaller unit would do.

It's pretty easy to do - it's the norm for a SS wash. You need a check valve or valves to keep the city pressure of the cold supply from going back into your gravity-feed tanks, and a solenoid supplied with cold water and wired to the "RINSE" position in the bay. That's pretty much it.

I asked because Mep001 said I would have a closed loop system. I was trying to clarify that it wouldn't be closed loop because new city water (with oxygen) would be circulating through the system. In my mind, closed loop is like a floor heat system or a closed boiler that is using a heat exchanger, meaning the city water never goes through the boiler. Am I wrong?

You're probably right - I was thinking of a system with a tank open to the atmosphere as an open-loop system, but that's not right either.

 

[MEP001]

Mep, I didn't have a problem with the pump supplying my zones, just the pump supplying pressure to the Takagi. You have to make sure you have a pump capible of 50ft of head pressure @ 10 gpm of flow when using a demand heater.

Thanks, I didn't realize the Takagi would have that much restriction to flow. You did mention a 95% efficient heater that has no restriction though, and that's mainy where my comment came from.

 

[mjwalsh]

2Biz,

Thanks for the PM. You are a lifesaver. I was looking at our boiler system in depth after hours quiet time last night & realized that I really should consider a combo Navien Unit ... the http://ecomfort.com/products/navien...ontent=11216&gclid=CK-7odTIz7YCFYU-Mgod1GYA_Q

I went through the documents on the Combo unit & I called Navien's tech support for pre sales info ... but I will still have to study it a bit more. Each facility has its unique specifics so like you say the spec's need to mesh with each other. On the boiler water side ... the PSI requirements are much less it appears than on the domestic hot water side. I don't believe I will have to add any more pumps nor need Navien's built-in tiny pump or buffer tank. It looks like I found the proper locations on the mechanical engineer's balancing reverse piping to get just the right placement of the 2 supplies & the 2 returns for the combo tankless. I won't celebrate yet though

mike

 

[2Biz]

Thanks, I didn't realize the Takagi would have that much restriction to flow. You did mention a 95% efficient heater that has no restriction though, and that's mainy where my comment came from.

All demand heaters have a high head rating because of the way they are designed. The water is "Thinned" down in the heat exchanger in order to transfer heat quickly, so this creates a lot of head pressure. Most of these Demand Heaters also have a restricting valve to limit volumn to maintain output temperature...Another restriction.

The 95% efficient condensing "Tank" style heater I was referrring to virtually has no head pressure. It is plumbed just like a standard domestic water heater (Cold water in, Hot water out) with the exception of a high efficient, high capacity condensing heat exchanger. The manuals to each one I linked to have a cutaway of how its designed if your interested.

 

[2Biz]

Okay- a new thought. I gravity feed the pumps meaning hot water for high pressure soap and high pressure rinse (no high pressure wax). What would be involved in trying to switch over to a system that only has hot water for soap and cold water for high pressure rinse. Seems like it might reduce the demand for hot water by almost half, meaning a smaller unit would do.

I was thinking the same thing, although I would also heat wax sinse I have it as a high pressure service. Why wouldn't (2) 1/2" N.O. Solenoids work and energize accordingly? (1) each on the hot and cold supply lines to each pump. N.O. in case one fails, it won't starve a pump. Although, They usually never fail closed. For a 4 bay, you'd need 8 solenoids, but Erie 3 ways would also work at half the total cost. Except I am trying to get away from the Erie's! My current MarkVII system is SO NOT user/maintenance friendly....

Thats why when I Pull The Trigger on a new boiler/demand heater, I will replumb my whole pump stand and get away from the 3" PVC tube manifolds that are the length of my pump stand. With my current setup, if the hot water worked, it would take over a minute for heated water to make it to the wands. Minimizing the supply hoses to the pumps to 1/2" will get hot water to the bays much much quicker.

 

[RockyMountain]

It's pretty easy to do - it's the norm for a SS wash. You need a check valve or valves to keep the city pressure of the cold supply from going back into your gravity-feed tanks, and a solenoid supplied with cold water and wired to the "RINSE" position in the bay. That's pretty much it.

It sounds great that it may be that simple, but I'm having a hard time visualizing it. Do you have a picture of how this might be done? I'm struggling to see how to get cold water to the pumps without having hot water from the gravity fed tanks enter also?

 

[RockyMountain]

Consider an Eternal tankless. I removed my 600k btu (I think) 82% efficient ( when new) boil and tank with recirculating pump with an Eternal mounted up on the wall. Very efficient (95% i think) and no maintenance. It keeps up with my 3 self serv and 1 automatic (presoak only). I set at 110 degrees, if it cant make 110 it lets water through ( so no starving pumps). I think it was $3500 installed.

Turbo
Chicago

So a new "best" option may be to re-plumb to cold water rinse and supply the "hot water" holding tanks with this type of unit that doesn't require a separate 80 gallon tank. Why heat 80 gallons of water in a holding tank and let it sit there? Heating just the high pressure soap would cut the supply needs in half. Supplying the current gravity tanks with a unit that would let water pass even if it is not quite at the desired temp would certainly meet my needs.

Any thoughts on this new solution?

 

[MEP001]

It sounds great that it may be that simple, but I'm having a hard time visualizing it. Do you have a picture of how this might be done? I'm struggling to see how to get cold water to the pumps without having hot water from the gravity fed tanks enter also?

This is what's on each pump:

The left is hot water with a check valve, the center is from the cold solenoid, the right two fittings are for soap/wax. To heat only the soap and not the wax or rinse you'd need a different setup, like separate hot and cold gravity tanks with an Erie valve to switch where it draws from. You can do it with solenoids, but I like the Erie valve because it can't fail to supply the pumps.

So a new "best" option may be to re-plumb to cold water rinse and supply the "hot water" holding tanks with this type of unit that doesn't require a separate 80 gallon tank. Why heat 80 gallons of water in a holding tank and let it sit there? Heating just the high pressure soap would cut the supply needs in half. Supplying the current gravity tanks with a unit that would let water pass even if it is not quite at the desired temp would certainly meet my needs.

Any thoughts on this new solution?

It works - I've done it with a Paloma and a $60 tempering valve.

 

[2Biz]

I downloaded the manual and spec sheet for the Eternal GU195 and they make no mention of internal head pressure in the heater. It is set up quite different than my Takagi, so I would have to call tech support to make sure the heater would “Full Flow” if it couldn’t keep up with the desired output temperature. Otherwise I would have a holding tank and circulator, you don’t want to starve a pump. Another thing to note, you are limited to ¾” plumbing which has to be factored in. The tank style A.O. Smith and Polaris I mentioned are plumbed with 1” fittings, twice the capacity of ¾”.

I guess the question is, whether to heat all water or have cold water rinse year round? OR heat water only in the winter and have cold water in the summer months? It would be nice for more experienced operators chime in and let us know how they do it and why…