advice : Boiler vs. Hot water heater

[soonermajic]

I recently scored a nice Lochinvar boiler & hot water holding tank, but have a relatively new Hot water heater I use. Question : should I sell the boiler (270k btu), & keep using my hot water heater (I run out of hot water sometimes) , or install the boiler? I do about 15 cpd in LaserWash & 25 cpd in manuals (so not very busy wash).

 

[Eric H]

I would think that the cost to install the boiler and tank would give you a very long ROI. Are the boiler and tank new? If it were me, i would sell the boiler and keep the storage tank for when the water heater fails. Install the storage tank and a tankless unit at that time.

 

[I.B. Washincars]

Install the storage tank and a tankless unit at that time.

I thought that one of the benefits of a tankless was that no storage tank was needed???

 

[Eric H]

The problem with tankless units is the burner takes a few seconds to turn on when hot water is called for. The float valves open up so quickly that too much water passes thru the heat exchanger while the burner is igniting and getting up to temperature. Then, because the float valve is wide open, it fills the holding tank very quickly and the tankless unit shuts off again. What ends up happening is the tankless unit only operates of a short period of time (which isn't efficient) and you also get a cold water sandwich in the pipe. By feeding the tankless unit into a storage tank you end up with a high efficiency water heater instead of a 80% eff tank type heater. The best solution right now (imho) is a high eff hybrid system that is a tank unit with a "tankless unit" built directly as one unit. The HTP Pheonix is a good example.

 

[soonermajic]

Have a neighbor that might want it to.heat their pool. Would this work for an avg sized pool, & would they need the holding tank?

 

[MEP001]

You don't use a holding tank to heat a pool.

If you use a 98% efficient on-demand heater to circulate with the storage tank, you'll come out ahead over either the water heater or boiler in terms of your gas bill. IMO the best option would be to sell the boiler and keep the tank.

 

[soonermajic]

I'm not sure what y'all are talking about, in terms of 98% efficiency tank /heater....? So I should sell my installed water heater, the boilers, keep the holding tank & install a tankless into my holding tank?

 

[2Biz]

What they mean is the heating system is 98% efficient. You only loose 2% of the heat out the exhaust. Its how they rate Efficiency. Since there is very little heat going out the vent pipe, it can be vented with PVC...When mine is running, the PVC vent pipe is barely warm to the touch.

I have the HTP Phoenix PH199-55. It is awesome! You can check it out here:

http://bostonheatingsupply.com/phoenixph199-55.aspx

With 1" NPT inlets and outlets, it has lots of flow capacity. Something to really consider if going the tankless route. They can be very restrictive.

 

[MEP001]

A typical boiler or water heater is about 80% efficient at best.

 

[soonermajic]

Friend couldn't use it for their pool, as they're on propane.

I wash about 15/cpd in Laser Auto & 20 cpd in SS bays. I don't need anything huge. What would you guys suggest, in terms of the H.E. gas heater? Then, would I still need to keep my holding tank?

 

[2Biz]

You really need to know how much hot water you can use worst case scenario....Or best case in our world! Once you know that, download the manual and go to the Performance Specification Page and determine which one fits your needs. You may need a bigger tank size because you have an Auto and need enough hot water to satisfy its usage. SS bays are easier to calculate. You also need to figure out if you can get enough flow out of 1" NTP fittings for your whole wash if all bays and the auto is drawing HW all at the same time. The HTP may not work for you or you could use it in conjunction with a holding tank if you need capacity/volume. But first you need to know what that volume per minute is.

After calculating what I needed I decided to upsize it to 199K btu. Only cost a few hundred more.

FWIW...This past winder, I had an exceptional weekend day where the bays were non-stop all day. We Used 3500 gallons that day, more than double any other previous day. Even at that usage, the HTP kept up and never ran out of HW.

 

[I.B. Washincars]

IMO, worry about what your auto needs. No one will know if your water heater is not keeping up in the SS bays. As long as the water is not ice cold, a customer is not going to know the difference.

 

[MEP001]

You should be able to convert the boiler to run on propane by changing an orifice.

 

[soapy]

I have 3 locations with htp type water heaters. Each has 2 autos and 3 or 4 SS bays and I never run out of hot water. March was very busy and all 3 locations had gas bills under $80.

 

[wash4me]

Just go to the plumbing supply house and get probably any hot water heater with a 75 gallon tank and 75-200000 btu. Should be 1200 to 3000 dollars.

 

[MEP001]

A 75 gallon water heater that's up to 200k BTU is going to be ANSI certified and will cost up to $10,000.

 

[Randy]

This is water heater we've been installing http://www.zoro.com/i/G2437863/ never run out of hot water. Any water heater over 199,000 BTU is classified as a boiler in Washington.

 

[2Biz]

When I researched hot water heaters, the Spiderfire was on the list along with AO Smith, HTP, and Polaris. The reason I settled on HTP was because it had a stainless steel tank and had a bottom mounted burner and heat exchanger. The Polaris also had a SS tank, but had bad reviews on the burner and ignition system. AO Smith and Rheem, used the top mounted burner and both had a glass lined tank, from what I remember. Rheem has 2” NTP fittings, which is good if you have auto’s and need flow.…

I work in a pretty large factory and they use the 120 gallon size AO Smith HE design to heat all the domestic water for the plant. Its about 20 years old and have never had an issue with it. Given that, I don’t know if you could go wrong with any of these water heaters…

 

[soonermajic]

great info & advice. I wonder what's the cheapest/smallest route I could go, for a small time 1/3 wash? 15 cpd on Automatic Laserwash.

 

[2Biz]

Do you know the maximum flow you need? Do you have float tanks? Or is your pumps pressure fed? There is a lot of things to consider when trying to figure out what will work. Knowing the CPD is only part of the equation.