How To Clean A RINNAI On Demand Tankless Water Heater
On Demand, or Tankless Water Heaters, run the water through a small heating surface. Like the elements in an electric water heater these Heat Exchanger Plates can built up with calcium and other deposits and reduce the heating ability of your Water Heater.
As I mentioned in a previous post, Water Heaters- Tank or Tankless, the flow is reduced on a Tankless water heater to maintain the output temperature. So if the heat transfer efficiency is reduced it will take longer the fill your machines and increase the cycle time of the washer.
Cleaning these water heaters involves a couple of hoses, a pump, some vinegar and some time. In the video I explain how the hose connections are set up and , hopefully, you have the correct valves installed that allow you to flush each unit individually without disconnecting any pipes.
It seems like the rubber hoses I used may have broken down a little with the vinegar and there may have been some debris in them as well. I had bought a 25′ garden hose and some new ends so I could cut the hose into the lengths I needed and when I was getting the tools out of my trailer I saw the hoses and thought “That will be easier” as just grabbed them and off I went.
If you are not sure that your hose will be OK in the vinegar cut a small piece and soak it in some vinegar for an hour or two and see if it is sticky, soft or breaking apart.
One thing you don’t want is the hose splitting open and vinegar spraying around.
The directions do recommend that your pump moves 4 gallons per minute. The pump I used was about half that as it was all I could find at a reasonable price. With a little more planning you may be able to find a small electric pump that will meet the requirements like this one HERE.
If you are using a drill pump it will be quite noisy and make sure that the ventilation holes are not covered so it will not overheat.
National Association of Home Builders- International Builders’ Show – Orlando Jan 2017
I spent a few days last week at the IBS checking to see if there were any new products that may work in the Laundromat / Coin Laundry Industry. And it was in Orlando in January.
I’ll start by telling you that it’s a big show. It covered the West and South Buildings of the Orange County Convention Center as well as some of the parking lot.
I arrived on Tuesday morning so I was able to head straight over and get started. I covered the South Building and had to speed through the last few aisles to finish up before it closed at 5.
Did I mention the parking? When I arrived around 11 I think they were almost out of spots. It took about an hour to actually get parked and that was after jumping a curb and finding a spot on the grass. So now at 5 everybody was leaving and it was jammed.
Total steps for the day.. about 17,000.
The next day was an early start and a trip through the main building. This was where the big names in bath, kitchen and construction supplies were set up. I have never seen so many toilets, faucets and door handles in one location.
I’ll skip through all of the details but today’s total was a little over 21,000 steps.
Now out of all that did I find anything of value for the Laundromat Industry?
A new trend in toilets has the tank installed inside the wall with only a “Flush Panel” and the bowl exposed. The flush panel allows access to the tank valves. Why would that be an option for a Laundromat? What if that 6″ you saved was the difference in getting the room ADA approved without having to move a wall?
They can be installed in new construction or renovations.
Another option is the Thetford WasteWater Transfer System. These are a great option if you need to move a toilet, restroom or install a new one and you don’t want to cut the concrete or maybe the sewer is not in the area.
This system uses a macerating pump to push the waste up or over to where you have a sewer connection.
There was a display that had an adjustable height sink as well. It can be used along with the in-wall tank toilet and allows the sink to be raised and lowered by pushing a button and using some slight force.
There was a number of the Water Heater Companies there as well including AO Smith, Rinnai, and American Standard.
As a mechanical- type guy I found the show pretty interesting. Doors, windows, taps and other flashy things didn’t really get my attention but the sections with building systems (ICF- Insulated Concrete Forms) always get my interest.
Time to rest my feet for the next big show.
Do you have Questions or Ideas for future posts or PodCasts?
In all of my stores I have Hot Water storage tanks. I say it this way as the setups are slightly different but the results are the same. I store around 100 gallons of Hot Water ready to go at a moments notice.
In two of the stores this is accomplished with a standard 91 gallon, 199,000 BTU water heater. It’s a big tank with a burner underneath to heat the water. The other store has a separate burner unit. This unit has an internal pump that pulls water from the tank, heats it and sends it back.
When I was building my newest store I focused a lot on getting the volume of water needed to the machines fast. This store has a much larger number of large capacity washers than my other stores and I was doing a complete renovation so this was the time to do it right.
Some back ground, Years ago I owned a 3 acre property beside a river. I wanted to install irrigation piping as it was very sandy and I wanted to grow a number of fruit trees and have a decent looking lawn. I talked to a few people about what piping to install, most suggested 2″ abs piping, you know the stuff that comes on big rolls. I did some calculations based on the length of piping and the pump I would be using (the pump was a high pressure irrigation pump) and my calculations showed I would not actually get water out of the far end of the pipe due to elevation changes and pressure loss in the pipe.
I talked to a local farmer that had literally miles of underground irrigation piping and his advice was that I would never complain if the pipe was too big. So I ended up installing 500′ of 4″ and 300′ of 3″ piping.
This was the same pipe used by utility companies. The initial cost was not that much more, it used the same trench and in the end I could spray water in 50′ diameter circles.
So with my latest Laundromat I used the same philosophy. The Water Department started it off for me. I needed a new supply from the main as I only had a 3/4″ connection. I asked for a 1 1/2″ but they only used 2″. So that was the base size for all of the piping right to the connections for the washers.
I explained to my plumber my reasoning and that every part of the system needed to be confirmed. The ball valves on the main piping were not a problem but I wanted to confirm the supply valves that the washer hoses connected to before he bought and installed all of them.
So why did I go with more traditional water heaters?
There is a trend towards on-demand water heaters in Laundromats and in many cases you need to install 2,3 or more of them. There are a couple of reasons for this:
#1- Two 3/4″ pipes don’t equal one 1 1/2″ pipe. To better explain this without getting too complicated I found this page in a search https://flexpvc.com/Reference/WaterFlowBasedOnPipeSize.shtml. With some standard pressures and velocity (Center , Yellow column) we can see that a 3/4″ pipe allows a volume of 23 Gallons Per Minute and a 1 1/2″ pipe has a volume of 81 Gallons Per Minute.
My 2″ pipe has a volume of 127 Gallons Per Minute.
So based on that alone you would need 4 on-demand units to allow the same amount of water to get to the washers with a 1 1/2″ pipe or 6 units for the 2″ pipe.
Chart number 2 on the page at the link above, takes out some of the variables and just shows the rate of GPM through an orifice, Here we see the difference between a 1″ and a 2″ as 53GPM and 329GPM (75 psi is the pressure at my store)
But that’s only one part of the equation.
#2- The Flow Rate through the water heater has to be determined. I did a search and pulled some information from a random On-Demand Water Heater:
“Maximum flow rate of 10.0 GPM at 35°F temperature rise (4.7 GPM at 70°F rise)”
So let’s break that down: Maximum flow rate 10.0 GPM- So now we would actually need 8 units to meet the capacity of our 1 1/2″ pipe or 13 units for the 2″ pipe.
But that’s not all it said….. “35°F temperature rise (4.7 GPM at 70°F rise)”. What does that mean? If you want to supply 120°F water the incoming water cannot be below 85°F. Now if your incoming water is more of a standard 50°F then you are only going to get 4.7 GPM. How does this happen? The Water Heater will reduce the flow through the unit to maintain the outlet temperature.
81 Gallons Per Minute divided by 4.7 = 17 Water Heaters.
But do I really need 80 to 100 GPM in my store?
Based on the chart we looked at above a 1/2″ pipe can move 14 GPM. Now the actual valve inside the washer may reduce this so lets say 10 GPM actually flows into the washer.
With a 1 1/2″ pipe and 17 On-Demand Water Heaters we could fill 8 washers at a time before we start to reduce the fill time of the washers. This means longer cycle times and less turn over during busy times in your store.
So why not stick with a tank system? And run it at a higher temperature?
A typical tank style water heater has a Recovery @ 70 F Rise of 277 gph or 4.6 GPM. Although the recovery shows the same numbers as the on demand the difference is that your volume of water through the Hot Water System is not reduced. So yes it is possible that the actual water temperature supplied to the washer is reduced this can be partially offset by setting the temperature to 140 instead of 120. And in either case the water sitting in the pipes will already have cooled so the actual in-washer water temperature will rarely be 120 °F.
At the end of the day it takes a certain amount of BTU’s to heat a certain amount of water, all other variables being the same.
So what does all this mean to us as Laundromat owners?
Everybody is in a hurry and they hate wasting time on mundane tasks such as laundry, also as Laundromat owners we want to move people through the store as quickly as possible. It all boils down to cycle time.
Let me take a quick bounce back to an old store I used to own. I had 2- 45# Milnor washers among a bunch of top loaders and smaller front loaders. The water supply had about 40 psi, a long run from the main and the hot water system had 2 older Paloma On-Demand Water Heaters. A normal cycle with each washer took about 28 minutes. Some days with other washers running I timed this washer at almost 50 minutes per cycle. Why? The cycle time does not run during the fill cycle of the washers. Now some of the old Dexters I had ran a 25 minute cycle and didn’t care if there was even water in the drum.
So back to our On Demand vs Tank questions? If you want to maintain your cycle times, keep your customers from waiting too long and keep your store flowing on a busy day you have to be able to get the water to the washers.
To do this with On-Demand Water Heaters you have to be prepared for a worst case and then maybe back off 20% or 30%. The odds of every washer willing at exactly the same time is rare but it’s possible to have 70% filling at the same time. You have to consider volume as well as number of machines. That 60#, 80# or 100# is going to take a while to fill so it’s possible for the customer to start 2 or 3 more machines. We have all seen it where the customer fills all of the machines, adds the money and hits start all at once. That’s actually how I tested my new store.
I understand the trend towards On-Demand and the savings by not having a tank of hot water being stored but what are the other impacts to the store? Slower cycles? Reduced customer turnover? Frustrated customers?
What if a customer sets aside an hour to wash and dry clothes before heading to work, no problem 25 minute wash, 30 minute dry, a few minutes to spare and they are off. No what happens when their washer is only at 19 minutes 35 minutes after it was started because the store is busy? Late for work or pack out wet clothes to the car? Do they care if the water was 105°For 120°F right now?
As with all of these posts these are my opinions but I hope to give you some background and help you with making decisions before you have a problem.
What’s your preference and why?
Pictures are used as examples only. Data supplied from various sources and is not intended to represent the pictured units.
Having your toilet paper disappear is frustrating for you and your customers, plus there is the cost involved. As I run 24 hour stores and only one is partially attended I have had my share of TP theft.
The dispensers I was using had a simple key with two prongs on it. This was easy to overcome with a screwdriver or possible a key or knife blade.
After a few issues as you can see on Facebook HERE . I was ready to try something different. After this issue HERE, when the door was damaged I used the opportunity to renovate the restroom and add some tile. At this point I found a toilet paper dispenser that had a more complex key.
You can purchase it on Amazon, they hold 2 of the large rolls and have a good lock for most places.
One of my unattended laundry’s has more of an issue with homeless people than the others, I believe that is why I have problems losing rolls of paper here.
About a week ago I went in and found both rolls gone, the cardboard sleeve and all. When I looked at the lock I saw where it had been gouged out at each end allowing both tabs to be depressed and the cover opened.
I didn’t have much time to do a pretty fix so I just grabbed a shackle and lock from a local hardware store and installed it.
The part is called a Double Hinged Hasp which allows it to move out of the way so you can open the cover and it also covers the mounting screws on the wall.
This shows how the hinges work.
Once it was all done it’s not as pretty as I like, I try to avoid this look as it portrays a security issue at your store but as I mentioned I only had a bit of time at with two $6 rolls of paper missing each night it needed to be stopped.
If you are having problems with the less secure key types I do recommend this one. It’s working great in another one of my stores and I have one to be installed after the remodel of one of my other stores.
One of the problems with vinyl tile floors in the Laundromat is that the glue is water based so if you get a small leak it gets under the tile and squeezes out when it gets stepped on.
In this video you can see how the tiles were getting loosened and where the source of the leak was.
The failures I have had on these valves have all been in the same place on the valve. Some valves fail due to solenoid issues, dirt in the lines and other similar issues. The main reason I have seen these valves fail has been due to a failure in the housing creating a mist of water spraying into the machine.
Over the past few days I have been running some tests on the various dryers at my stores. The question that came up was, How much does it actually cost to run a dryer? We all know how much we charge based on the amount of minutes per quarter or cycle but are we really making a profit?
After some thought I figured I would determine the amount of time the gas valve is actually on and then do a bunch of math to figure out how much it costs per cycle.
The cost came from the December 2016 Gas Bill from one of my stores.
100’s of Cubic Feet : 522 1 ft3 = 1000 BTU’s Cost: $605.61 Cost Per 100 Cubic Feet $1.61 Cost Per Therm $1.12
$ per Ccf divided by 1.032 = $ per therm
Although I didn’t use therms anywhere in the final results it is a common unit that gas is charged to the consumer. It’s a good number to calculate and understand when talking to owners around the country.
Here are the results:
Now there are some that may read this and say that we should only be charging $0.25 for a dry. But as business owners we realize that there are a lot of overhead costs involved and gas is just a piece of the puzzle. Power, repairs, equipment depreciation all add to the final customer price.
There were a few things that surprised me a little, I expected the empty dryer cost to be higher then the full dryer as the air/heat would be blowing right through but after the test and thinking about it I realized that the wet clothes absorb a lot of heat and it takes awhile to get the temperature up to where the burner turns off.
So no more complaints about people running a dryer with only a couple of items in it.
And next time a salesman tells you that you can pay part of the loan for your new dryers with the utility savings ask them to show you the numbers that prove it.
Hope this helps.
If you have a chance take a look at the Resources Page and see if there are any items that will help you with your business. If there is something missing please let me know. That’s how I keep this part of the business going.
How much gas does it take to run a dryer in a Laundromat? And what does it cost?
The dryers do have a BTU/ hour rating listed on the name plate and we can do calculations based on that but we know the burner cycles on and off depending on the amount of clothes, the water content of the clothes and the outside temperature and humidity.
So I decided to go to the source. The gas valve. How long is it actually on.
Other uses for this would be to connect to your water heater to determine an average weekly gas usage. This will help you isolate the Hot Water Cost from the dryer cost.
There are a couple of setting on this depending if you want to track down to the second. The directions look a little confusing but they cover a few different timers and a coupe of languages. So just find your timer part number and follow the steps.
As part of some dryer testing I have been doing I used my Thermal Imaging Camera to look at the dryers and some hot spots.
The link for the camera is below. There has been a lot of advancements and therefore price reductions in these cameras. The one I have is connected to my phone so you can record pictures and video or do a split screen between the phone camera and the Thermal Imaging Camera.
Check it out…
The camera is available HERE. I use a camera from SEEK Thermal. It’s connected to my iPhone (Android are also available) and uses a Free App for all of the functions.
Here’s a split screen shot I took to give you an idea. The alignment is off slightly due to the different camera locations (top and bottom of phone).
I’ll post the results of my dryer testing soon. I’me trying to find out the difference in gas usage.