Winter morning, you are all ready for a hot shower and suddenly find your Takagi water heater not igniting. Takagi is a reliable brand but still, issues with the Takagi heater like not turning on or not igniting are very common. So, what are the possible causes of your Takagi gas water heater not igniting?
- The computer board not receiving power
- Insufficient flow rate
- Clogged cold water inlet filter
- Issues with the gas line
Now to fix the issues first make sure there is enough power and gas supply. Next, make sure the flow rate is above 0.5 gpm, or replace or clean the filter in the cold water inlet.
Are you finding it a bit complex? You should because there are more reasons and more solutions. Just read this article and you’ll properly understand the way to fix the issue along with the Error code fixation guide.
Table of Contents
Takagi Water Heater Not Igniting: General Reasons
Takagi water heater not igniting is a very common problem and here we’re at the main segment to explore it. First, we’re going to discuss the major reasons behind this. More or less the reasons are almost the same for all types and models of Takagi water heaters. So, whether you are using the TK series, CT-199 series, or, 540P series, you can follow this guide,
| Reason | How to Fix |
| Power Button Not Turned On | Check the power button on the heater or remote, and switch it to “on.” |
| Computer Board Not Receiving Power | Ensure the ON/OFF switch below the fuse box is on. Check and replace a blown fuse with the same rating. |
| Insufficient Flow Rate | Verify flow rate above 0.5 gpm. Increase hot water use to boost flow. |
| Clogged Cold Water Inlet Filter | Clean or replace the filter in the cold water inlet as per user manual instructions. |
| Blown Fuse in the Fuse Box Assembly | Inspect and replace a blown fuse of the same rating. Check the ON/OFF switch below the fuse box is set to “on.” |
| Return Water Temperature in Recirculation | Check incoming water temperature using the INFO button. Adjust the recirculation system for cooler water if the temperature is too high. |
| Gas Line Issues | Ensure the gas line supplying the water heater is open. Purge air from the gas line if suspected. |
| Hot and Cold Water Connections Reversed | Confirm hot water is connected to the hot water inlet and cold water to the cold water inlet. |
| Disconnected Clear Hose | Check both ends of the clear hose connecting the proportional gas valve to the combustion chamber. Reattach if disconnected. |
| Recirculation System Issues | Ensure a check valve is installed and functioning correctly between pump discharge and cold water supply. Check for valve issues. |
| Flow Sensor Problems | Check the impeller of the flow sensor, ensuring it’s functioning properly, especially if the fan doesn’t initiate despite power being supplied. |
Reason 1: Power Button Not Turned On
Sometimes, the reason your Takagi water heater won’t ignite is because the power button isn’t switched on. This can be a button on the heater itself or a remote control if you have one.
How To Fix It?
To fix this, find the power button and make sure it’s in the “on” position. If you’re using a remote control, make sure its power button is also turned on.
Reason 2: Computer Board Not Receiving Power
Inside your water heater, there’s a part called the computer board. It requires electricity to work correctly. If it’s not getting enough power, your water heater won’t start and ignite. You can see if it’s getting power by looking at some LED lights on the computer board or on the remote controller.
How To Fix It?
To solve this, make sure the ON/OFF switch below the fuse box is set to “on.” Next, look at the fuse inside the fuse box assembly. If it’s blown, replace it with a new one having the same rating.
Reason 3: Insufficient Flow Rate
Your water heater requires a certain amount of water flowing through it to work. If there’s not enough water flowing, it won’t start heating. We measure this flow rate in gallons per minute (gpm).
How To Fix It?
To deal with this check the flow rate and make sure it’s above 0.5 gpm.
Tip: Try using more hot water in your home, like turning on more hot water taps. This can increase the water flow and might help the water heater start working.
Reason 4: Clogged Cold Water Inlet Filter
This is an unusual reason but can happen sometimes. In the cold water inlet of your water heater, there’s a filter. If this filter gets blocked with dirt or debris, it can stop water from flowing properly and prevent the heater from working or igniting.
How To Fix It?
To solve this issue, check the filter in the cold water inlet. If it’s dirty, follow the instructions in your user manual to clean it or replace it.
Reason 5: Blown Fuse In The Fuse Box Assembly
Here is another common reason I generally found while troubleshooting the Takagi water heater ignition problem. If the fuse of the water heater blows, the heater won’t work. This can happen if there’s an electrical issue.
How To Fix It?
To fix the issue, inspect the fuse box assembly and check for a blown fuse. If you find one, replace it with a new fuse of the same rating. Also, ensure the ON/OFF switch below the fuse box is in the “on” position.
Reason 6: Return Water Temperature In A Recirculation System
If your water heater is part of a recirculation system, it may not turn on or ignite because of some rare causes. For example, if the temperature of the water coming back into the heater is already close to the desired hot water temperature, an ignition problem may occur.
How To Fix It?
Check the incoming water temperature using the INFO button on the front of the unit. Press the INFO button until the arrow points to “IN.” You can also check the “error code indicator” in the manual. It should look like this –
If the incoming water temperature is too high, consider adjusting the recirculation system to provide cooler water to the heater.
Reason 7: Gas Line Issues
Gas line issues are another common problem. Your water heater needs a supply of gas to operate. If there’s a problem with the gas line, such as it being closed or having air trapped in it, the water heater won’t function or ignite.
How To Fix It?
Ensure that the gas line supplying your water heater is open. But if you suspect there’s air in the gas line, then purging the air from the gas line is necessary.
Reason 8: Hot And Cold Water Connections Reversed
If the hot and cold water connections to the water heater are mixed up or connected backward, it can prevent the water heater from detecting water flow correctly. Water flowing backward through the heater is not sensed by the flow sensor, and as a result, the water heater won’t work or ignite.
How To Fix It?
Check the water connections to the heater to make sure they are not reversed. The hot water should be connected to the hot water inlet, and the cold water should be connected to the cold water inlet.
Reason 9: Disconnected Clear Hose
There’s a clear hose that connects the proportional gas valve to the combustion chamber of your water heater. If this hose is disconnected, your water heater may not light up.
How To Fix It?
To fix the issue, check both ends of the clear hose to make sure it’s securely connected. If it’s disconnected, reattach it.
Reason 10: Recirculation System Issues
If you have a recirculation system for your hot water, it needs to be set up correctly. One important element is the check valve, which prevents cold water from mixing with the hot water. If this check valve is missing or not functioning, it can cause issues like ignition problems.
How To Fix It?
Confirm that a check valve is installed between the pump discharge and the connection to the cold water supply. Check for any issues with the check valve. If it’s not working correctly, it can allow cold water to flow back into the system.
Reason 11: Flow Sensor Problems
The flow sensor is a part of your water heater that detects water flow. If it’s not working properly, it can prevent the heater from starting, especially if the fan doesn’t initiate.
How To Fix It?
If the fan doesn’t start and you’re sure there’s power to the unit, it might be a problem with the flow sensor. Check the flow sensor to make sure its impeller (a rotating part) is functioning correctly.
Takagi Water Heater Ignition Failure: Error Code 111
Your Takagi tankless water heater can sometimes face ignition problems and you can notice it by seeing an error code 111. You can detect it by noticing 3 flashes on the computer board. In this segment, I’ll break down the steps you can take to troubleshoot and resolve this issue.
1. Check The Hi-Limit Switch
When your heater displays an ignition failure, the first thing to do is check the hi-limit switch. To do this, follow these steps:
- Turn off the power to the heater.
- Locate the white button on the hi-limit switch and press it. You should hear a click; this indicates the switch has been reset.
- Turn the power back on and test the heater. If it fires up, the hi-limit switch might have been the issue. If it happens again, contact the Technical Service Department for further assistance.
2. Verify The Gas Supply
Next, ensure that your heater is receiving an adequate supply of gas. Also, make sure that the gas line is free from debris or air. You may need to purge the line of air if necessary.
- For natural gas units, check for a faulty pressure regulator at the gas meter.
- If you use propane, remember that cold weather can affect the regulator and cause ignition problems.
3. Check Gas Supply Pressure
Aside from gas supply. check if the gas supply pressure meets the specified requirements when the heater is both in standby mode and running.
4. Inspect The Proportional Gas Valve Connection
Check the clear plastic tube connecting the proportional gas valve to the combustion chamber. Make sure it is securely attached.
5. Examine The Overheat Cutoff Fuse (OHCF)
If the OHCF has been compromised, it could lead to ignition failure. To check If it’s compromised, contact the Technical Service Department for further guidance.
6. Clean The Flame Sensor
If your heater’s flame only stays on for a short period before going out, it may be due to a dirty flame sensor. Clean the flame sensor properly in order to fix the issue. You can check my other article on Takagi water heater maintenance for a better guide.
7. Check The Igniter
Ensure that the igniter produces a spark. You can view this through the sight glass located next to the igniter and flame sensor:
- A strong blue spark should remain steady and in place.
- A weak spark may jump around. If no spark or a weak spark is observed, check the igniter wire connections and make sure they are secure. If they are secure, you may need to replace the igniter.
8. Look For Venting Blockages
Inspect the venting system for blockages, such as bird nests, animals, or debris.
9. Possible PC Board or Gas Solenoid Fault
If you’ve tried all the above steps and the problem persists, it could be a PC board or gas solenoid fault. In this case, contact the Technical Service Department for professional assistance.
FAQs:
How do you test a tankless water heater ignitor?
To check if the tankless water heater ignites, look for the ignition switch at the front center of the heater. It should be near the drain plug on the left side. Turn on the power switch, then lift this switch and listen for a spark from the electric igniter. That spark shows if the heater is starting up.
How do I know if my tankless water heater is gas?
To find out if your tankless water heater uses gas, check for a pilot light or an exhaust pipe at the top. If you see either of these, then it runs on gas to heat the water. If you don’t see these parts, it’s an all-electric unit.
What is the electronic ignition on a water heater?
The electronic ignition on a water heater works in a specific way. It only starts up when necessary. So, it lights up and uses power only when the water heater, burner, or boiler requires heat.
Final Verdict:
So, here I’ve mentioned all the reasons and solutions for the issue – the Takagi water heater not igniting. I’ve separated the article into 2 parts. The first part explains all the general causes and solutions and the next part is all about resolving the error code 111 or ignition failure issue.
My years of experience say mostly this happens due to low maintenance. So, always keep your water heater under proper maintenance. Now before I finish the article I am suggesting another article on the dip switch settings of the Takagi water heater.