Eccotemp Systems 40H, 40HI Troubleshooting Manual

40 Model Comprehensive

Troubleshooting Guide

Eccotemp Systems, LLC

315a Industrial Rd. Summerville, SC 29483

www.eccotemp.com

1-866-356-1992

Listed below are some common questions and troubleshooting guidelines for our 40H/HI water heaters. Always remember
when working on a particular issue to ensure that the water heater is unplugged and the gas is shut off. Always seek
professional advice and assistance, if needed. Also, you are welcome to call Technical Support at 866-356-1992 or, for
fastest service, submit a support ticket by going to www.eccotemp.com and clicking on the “Support,” tab on the right side
of the page.

Basic Information:
The 40H and 40HI are gas powered tankless water heaters. After setting them to the desired temperature, they will self
adjust, based upon water flow, to maintain a desired temperature. They are designed for residential use for a 2 bath, 3
bedroom home. Though capable of achieving higher temperatures, it is recommended that you set the temperature at 120
degrees Fahrenheit or below.

General Questions:
Questions:

Q. I want to mount inside my camper or food truck?
A. Remember, the 40H and 40HI were designed for residential, not commercial, use. The 40HI is made to be mounted
indoors. However, DOT Regulations state that you cannot have a tankless water heater hooked to a gas supply line while
in motion. Once stationary, you can then hook up the gas supply and use your 40 model water heater.

Q. Can I use a 40H or 40HI with a portable propane tank and rubber hose?
A. Trying to use a 40H or 40 HI in this way will not meet building code, will reduce performance, can result in gas related
error codes, or damage to the water heater.

Q. Will it work on a 12v supply pump?
A. Yes, as long as your pump is capable of providing adequate water flow and water pressure. The 40 model water
heaters need a minimum of ¾GPM and 20PSI to operate.

Q. Can I use the 40H or 40HI with my existing plumbing?
A. The water heater has ½” NPT fittings so it is easily plumbed in to existing lines.

Q. Can I use this water heater to heat my swimming pool or hot tub?
A. You can use an 40H or 40HI to generate hot water for any application. Attempting to use it with a recirculation system
for an application like this will void your warranty and permanently damage your water heater.

Q. Can I use to this water heater in a recirculation system at all?
A. No, this will void your warranty and permanently damage your water heater.

Q. What size venting do I need for a 40HI?
A. The 40HI requires 3” Cat II/III stainless steel venting. Please check your local building code.

40 Model Comprehensive

Troubleshooting Guide

Eccotemp Systems, LLC

315a Industrial Rd. Summerville, SC 29483

www.eccotemp.com

1-866-356-1992

Thank you for contacting Eccotemp Systems Help Desk. Our goal is to provide you with the best customer service
possible.

If your 40H/HI has been working fine but is now having issues, ask yourself this question: What has changed?
There are a few basic things which can affect the operation of a tankless water heater, which are listed below.

1. Clogged filter screens

2. Low water flow

3. Single knob faucets

4. Incorrect gas type or gas pressure

5. Low or empty gas tanks

6. Issues with the electrical supply

7. Recent power surges (i.e. lightning)

8. High temperature setting

9. Blockage in the exhaust

If any of these things seem possible, then please check to see if it applies through troubleshooting prior to calling
customer service.

The first and most important thing to do is to make sure the gas being supplied to the water heater is correct for
your model. There is a plate on the side of the water heater which will provide the gas type that it was designed to
be used with. This plate will either say NG for Natural Gas or LP for Liquid Propane. Do not run your water heater
with the incorrect gas type.

Make sure the temperature is set to 120 degrees or below. The 40H/HI will overheat with low water flow. If this is
happening, remove any filter screens that are installed in your faucets and see if that alleviates your problem.

40H/HI is experiencing issues, but only at one faucet:

Is there anything different between this faucet and the other fixtures that are working properly? Usually this is attributed to
too little or too much water flow. Specifically if the water heater is overheating or shutting down during operation, check the

filter screen in your faucet and free up your water flow as much as possible. This can also be directly related to the faucet

being a single knob faucet. Again, free up your water flow as much as possible.
40H/HI will not turn on and doesn’t have anything on the display:

If your water heater does not show anything on the display and will not run, you most likely have an electrical issue. Check
to make sure that the main breaker supplying power to the outlet is not tripped. Also, if the power outlet that your water
heater is plugged into has an incorporated breaker, make sure that it is not tripped. A very easy way to test to make sure
the outlet is working correctly is to plug a different electrical appliance into it and see if it will turn on.

40 Model Comprehensive

Troubleshooting Guide

Eccotemp Systems, LLC

315a Industrial Rd. Summerville, SC 29483

www.eccotemp.com

1-866-356-1992

After verifying that your water heater has power going to it, you can check the internal wire connections. First, unplug
your water heater from the electrical outlet. After doing so, remove the cover by taking out the four screws on the front
which hold it in place. On the indoor models the digital display is attached to the cover, so please be careful as to not
damage the connections. Once the cover has been removed, check the wire connections throughout the water heater to
make sure everything is plugged up and secure. If it looks like there is a build-up of corrosion, unplugging and re-

plugging the connections verify they are correct. Note: the computers are interchangeable between the indoor and

outdoor models. The main difference is that the indoor models connect directly to the computer board and the outdoor
models connect to a set of green wires coming from the computer board. On the 40HI, there will be a green wire that is
not connected to anything and on the 40H there will be a wide white ribbon wire that is not connected to anything. This
is perfectly normal.

Lastly, if you then test your water heater and it does still will not come on, you will need to remove the computer board
and check to make sure the fuses are intact. Again, make sure that you have unplugged the power cord so there is no
electricity going to it. Inside, there is a grey box that is located near the top right. Remove the two screws from the front
of the board and it will slide out freely. On the computer board you will see two rubber boots which cover and protect the
fuses. Pull these boots off and, if the fuses are still in working order, there will be a thin wire that is visible inside of them
and should not be broken. If the wire is broken, you will need to replace the fuse.

If these steps do not fix your issue, please call technical support at 866-356-1992.
40H/HI is displaying set temperature, but will not come on:

This means that your water heater is not seeing that there is water flowing through it. The most common reason for this
is low water flow. To determine if this is the case, turn on two faucets and see if your system turns on. If this works, you
probably have clogged filter screens. Check all of the filter screens in your faucets to see if they have become clogged
over time. If you remove the filter screen from a faucet, turn on the hot water at that location, and the system runs, you
can always just not reinstall the screen and use the faucet in this manner. Next, check the filter screen that is in the
water heater itself. There is a drain plug where the inlet water pipe enters the water heater. There is a screw located on
the front of the plug, inside of it. Do not try to loosen or tighten this screw. The entire drain plug will unscrew and can be
removed. Once removed, you will see a filter screen with a magnet in the center of it. If dirty, they can both be cleaned
by gently using a wire brush. If you need a new filter screen, you can order one from our website at

www.eccotemp.com.

Lastly, you will need to check your flow sensor to verify that it is working properly. Go to the 40H and 40HI
Troubleshooting section on the forums page. This is located at https://eccotemp.zendesk.com/forums. You will find a
Flow Sensor Installation Guide which will help in completing this task. Follow the instructions in the guide to remove the
flow sensor. Once removed, you can blow through the flow sensor to verify that the impeller inside of it is spinning freely
and there is no debris inside of it. Reinstall the flow sensor as the guide instructs and test the water heater.

If these steps do not work, please contact technical support at 866-356-1992.