Instant Hot Water Heater?

Buying a 4 bay SS wash. Currently it has 60 gallon water heater which appears in good condition but I want your opinion on installing an instant hot water heater. Will an instant keep up with demand. I am buying this as a long term investment and I understand gas prices will continue to increase over the years. I will also be researching to see if there are any tax advantages on the installation. Any and all help greatly appreciated.

How old is the water heater currently installed? If it is modern unit with electronic ignition and automatic damper I doubt it will save you enough money to make a reasonable ROI to replace. They are fairly efficient and heating and retaining heat. It would certainly be worth looking at once the old one bites the dust.

I replaced a boiler for someone with a Paloma 199k BTU instant heater. I set the heater to 140° and used a tempering valve to mix that with cold water to get the required temperature. It had no trouble at all keeping up with all four bays running. The whole setup cost less than $1,000. It's no more efficient for operating purposes, but it saves a little over time since it's not keeping water hot on a rainy day or at night.

I have several 199K palomas operating and they will only produce about 5 gallons per minute each with a 60 degree raise in water temp. No way that one unit could supply a whole wash with enough hot water. I have also used palomas for my house and it will only keep one shower running at a time with hot water. I use one paloma per bay and they do fine for that.

That's why I used it set at 140° and used a tempering valve. It's rated to heat 7 GPM directly so that obviously can't supply a 4-bay wash, but heating the water above the needed temperature and mixing it with cold to get the needed volume does work.

I was looking at possibly installing a commercial instant hot water heater that is rated at 14.5GPM. Expensive up front, but I am in it for the long haul. I have my accountanr looking to see if there any tax incentives for the upgrade.

The operational costs for an instant heater won't be any less than a boiler or large water heater because the efficiency is about the same. All the savings come from not maintaining hot water. If your goal is to save money, look into a high-efficiency on-demand heater. There are units that are 98% efficient (Standard heaters are around 80%).

Blakelyfg - what is the model you are considering? I am thinking the same thing for my 2 bay self serve (attached to my IBA's). Haven't found an on-demand gas HWH with that high of a rating yet.

My SS cat pumps are rated at 4gpm each, but by my estimation are running more like 3.5gpm. Rinnai says there RC98Hpi can put out 7.5gpm with a 50deg temp rise. Since 90deg water is warm enuf for me, and the coldest it ever comes in at is 40 deg, it seems like this should work. I would be sure not to starve the cat pumps for water by using a cold water mix if needed when the Rinnai couldn't keep up. So if by chance both bays were being used, on the hot water function, at the same time, the temp might fall a little, but not enough (I feel) for the customer to be upset by it.

MEP1 - can I get a more detailed explanation of how you setup your units?

M