Water Heater Problems

Residential water heaters, being an appliance with various components and types, are subject to different problems that can be hard to troubleshoot. If your water heater is not working properly, it is best to call a qualified service technician rather than attempt to perform maintenance or repair yourself. In order to familiarize yourself with the range of problems that can happen, and possible causes, we have compiled the following list to help troubleshoot water heaters.

Water Temperature Excessively High

This can be caused by the thermostat being set too high, in which case you can try lowering the thermostat, one of the few items here that be done yourself. Not only will the water be more comfortable, you will also save energy. Just be sure to lower the setting a degree or two at a time, since you can easily make the water too cold and then you will have to use more energy in heating the tank back up. Other causes include a leaking thermostat valve, the remedy for which is to have the valve cleaned or replaced, a thermostat which needs to be recalibrated, a pilot light set too high, or a pilot light gone out.

Insufficient Amount of Hot Water or Water Too Cold

If the hot water runs out too soon or just plain isn’t hot enough, then the thermostat on your hot water heater could be set too low. This is an easy fix, just set it higher. But - Never set the thermostat higher than 120 degrees F; you could cause the water heater to overheat, not to mention the risk of scalding to your home’s occupants and family members.

Also:

- The thermostat may be out of calibration (replace thermostat or have it recalibrated).
- The burner opening may be clogged (have it inspected and cleaned)
- Your water heater may be undersized for the house (Need to replace with larger, higher capacity unit)
- Gas pressure may be too low (gas supply pressure and manifold pressure should be checked)
- Flue may be clogged (needs to be inspected and cleaned)
- Thermostat defective (replace the thermostat)
- Dip Tube Defective (replacement)
- Draft venting situation (check for updraft and downdraft venting and correct if needed; drafts can blow out pilot light)

Pilot Light Will Not Ignite

If the pilot light has gone out and you can’t relight it, fist of all, the gas supply may be turned off, so check to ensure the manual valve is open, which turns on the gas supply. Failing that, then the following may be happening:

- The thermostat may be out of calibration (replace thermostat or have it recalibrated).
- Pilot tube pinched (replace or repair pilot tube)
- Pilot tube clogged (replace or clean pilot tube)
- Gas valve defective (replace the gas valve)
- Gas line has air in it (air needs to be flushed from line)
- The burner opening may be clogged (have it inspected and cleaned)
- Dial on gas cock may be set improperly (set gas cock knob to correct position per lighting instructions)
- Safety magnet assembly defective (check magnet, replace gas valve if required)
- Thermocouple connection is loose (check and tighten connection)
- Defective thermocouple (inspect and replace)
- Defective automatic pilot valve (inspect and replace)

Burner Flame Noisy

A defective regulator may need replacing, the burner opening may be too wide and need replacing with one having the proper size, or the pressure regulator may be set too high and need to be reset.

Burner Does not Turn Off

- The thermostat may be out of calibration (replace thermostat or have it recalibrated).
- The thermostat may be set overly high (lower the thermostat setting)
- Defective thermocouple (inspect and replace)
- Thermostat valve seating may have dirt on it (replace or clean)

Pilot Light Not Staying Lit

The reasons for a pilot light that will not stay lit are much the same as for one that will not light at all, with a couple of added possibilities:

- Dirt in pilot opening (clean opening so that it is clear of obstruction)
- Flue may be clogged (needs to be inspected and cleaned)
- Draft venting situation (check for updraft and downdraft venting and correct if needed; drafts can blow out pilot light)
- Excess of primary air (check pilot light shutter and adjust as required)
- Safety magnet assembly defective (check magnet, replace gas valve if required)
- Thermocouple connection is loose (check and tighten connection)
- Defective thermocouple (inspect and replace)
- Drafty conditions (reduce the draft in the area or install shielding around pilot light)
- The thermocouple tip may be out of the pilot flame (adjust tip so it projects into flame)
- Pilot tube partially clogged (replace or clean pilot tube)
- Defective automatic pilot magnet assembly (check magnet, replace gas valve)

Burner Not Staying Lit

If the main burner of the water heater does not stay lighted, there are several potential causes to be investigated. Check the gas pressure to see if it is too low and take steps to get the proper pressure for the specific burner. Also check for:

- Damaged or pinched main burner’s gas supply tube (replace or repair)
- Opening in burner may be clogged (replace or clean)
- Insufficient gas supply pressure
- Defective thermocouple (inspect and replace)
- Thermocouple connection is loose (check and tighten connection)
- Safety magnet assembly defective (check magnet, replace gas valve if required)
- Clogged main burner’s gas supply tube (replace or clean)

Water Under Water Heater

If you are seeing puddles or drops of water on the floor around your gas water heater, which later dry up, there is no need to worry, as this is a normal condition. If the water does not dry up and is continuously present, however, the following conditions need to be considered. There may be a defective joint somewhere, particularly at the cold water intake or hot water outlet fittings on the tank, inspection is needed and repair could be required. Another source may be small pinhole leaks in the inner tank, in which case the entire water heater will need to be replaced. If an immersible thermostat or anode rod is loose, tightening or replacing them may remedy the situation. A defective pressure relief valve may also be at fault.

Our Most Popular Online Tips