To serve you better, we remain open 24/7 during the COVID-19 outbreak. Learn More

Gas Water heater troubleshooting tips

Few water heater troubleshooting tips can save you from a service call

Before you do any gas hot water heater troubleshooting make sure there is no gas leak. Natural gas leak can be very dangerous. If you smell gas near the gas water heater, shut off the pilot light, close the main gas valve and do not activate any electrical power switches not even lighting. Call gas utility immediately.

Basic gas and electrical knowledge are necessary for proper water heater troubleshooting. Make sure your gas is off when doing troubleshooting. Refer to the water heater manual for more details.

No hot water

Check that you have gas in your house and to the water heater directly; the main gas valve might be closed causing no hot water. If you suddenly have no hot water, your water usage may have exceeded the tank capacity. If that is the case, wait for water heater to recover to take a shower or to do dishes. Another problem related to no hot water issue is that your pilot light has gone out. Relight your pilot flame according to the instructions printed on the unit.

Pilot light doesn’t light or doesn’t stay lit

One of the most common water heater troubleshooting is checking that there is a gas at all coming to water heater or is the gas pressure low. If there is a problem with the gas supply, call the utility company. If there is an air in gas line, it will need to be removed from the gas line and should be done only by certified gas technician. Most issues with the pilot light can only be fixed by a professional. Do not try to fix it yourself as it can cause even more issues. Call heating expert for a service.

Lack of Oxygen

Hot water heaters require sufficient supply of fresh delivered for gas combustion for a proper operation. The air enters the gas chamber form the bottom of the water heater and needs to enter the flue vent that is below the draft hood. If there is no sufficient fresh air supply there can be a pilot light outage, yellow burner flame, possible presence of carbon monoxide and smell of burnt gas in the furnace room. Check the room to ensure sufficient supply of fresh air and make cuts in the walls to put grills for the air to enter the room. Do not cover water heater with the insulation blanket and check space for any possible obstruction.


Condensation can happened when large amounts of hot water is used continuously and also when gas is burning and flues gases cool down and result in the condensation. Condensation often happens when hot water heater is filled with cold water for the first time. You may see water dripping around the water heater as a result of condensation, water on the vents and top of the water heater. If condensate drips in to the burner you will hear a sizzling noise. To solve the problem and to do water heater troubleshooting you will need to raise the supply air temperature, water temperature inside the water tank or even increase the size of your water heater (it makes sense of your existing water heater is old and you don’t have sufficient supply of hot water).

Burner won’t stay lit

The main reasons why burner won’t stay lit is high temperature in the room, blocker or dirty air intake and blocked flame arrestor openings.

Check Vent System

Venting system always has to have positive or horizontal slope. Your exhaust vents cannot be negatively slopped as this can cause carbon monoxide leakage. Properly installed venting system is very important in the safe operation of your water heater and its efficiency. If you notice an issue with your vent system call professional to fix it.


Having an issue with your existing hot water heater? Not sure how to do water heater troubleshooting on your own? Call an expert DeMark Home Ontario professionals will be happy to assist! Call Today 647-847-2998


Customer Rating of 5.0
based on Google reviews

  • Get A Quote Today! Free in-home estimate!
  • This field is for validation purposes and should be left unchanged.

Upgrading to a high-efficiency heating and cooling system offers more than energy savings.

Take advantage of these rebates today!


This item comes with absolutely free standard installation. We’ll ensure that the product is completely installed to code and fully functioning prior to leaving.


Great news! Receive a brand new digital thermostat absolutely free when renting this HVAC product from DeMark Home Ontario.


Great news! When renting a furnace or air conditioner, you’ll get your first 2 months absolutely rent free.


Great news! When renting a furnace and air conditioner together, you’ll get your first 3 months absolutely rent free.


This product carries a manufacturer warranty and we’re happy to explain it in full to you. Feel free to get in touch with us for more information or see the Warranty Information tab for more information


If your order is placed and confirmed by 11am, we can have your HVAC product installed within the same day.

Certain conditions apply, not available on all products.


This water heater is subject to reduced rental rates based on the DHO discount program. Save money on your bill every single month!

Some conditions apply


Save money on this item when buying it along with a qualifying high-efficiency furnace or air conditioner.

Some conditions apply


Great news! When renting a qualifying water heater, you’ll get your first 2 months absolutely rent free.


Promotional code can be found on the eFlyer, Brochure or promotional email that you received from us.

*If you are an existing customer please refer to the mail or email that was sent to you after the installation of your equipment as it contains your promotional code. If you are having troubles locating it please call us and one of our Customer Service Representatives will be happy to assist you.

  • Please fill out the form below in order to schedule service and be sure that your request will be processed promptly and you will hear back from us shortly.

Notice for Power Vent Water Heater Customers

Effective August 2007, gas code requires technicians working on venting to replace black ABS vent pipe with white UL-certified vent pipe.

We will upgrade your venting pipes at no additional cost.

  • Forum Registration

  • Forum Rules

    Registration to this forum is free!
    You must abide by the rules and policies detailed below. If you agree to the terms, please check the 'I agree' checkbox and press the 'Register' button below.

    Although the administrators and moderators of DeMark Home Ontario Forum will attempt to keep all objectionable messages off this forum, it is impossible for us to review all messages. All messages express the views of the author, and DeMark Home is not responsible for the content of any message.

    By agreeing to these rules, you warrant that you will not post any messages that are obscene, vulgar, sexually-oriented, hateful, threatening, or otherwise violative of any laws.

    The owners of DeMark Home Ontario Inc reserve the right to remove, edit, move or close any thread for any reason.



Send this to a friend