Give Your Customers Boiler and Water Heater Peace of Mind

As the cold of winter sets in, your customers are going to want to make sure their boilers and water heaters won’t fail them soon. Here are some maintenance tips to keep in mind for your service calls.

Give Your Customers Boiler and Water Heater Peace of Mind

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If you do an online search for water heater maintenance, the internet provides a homeowner with just enough information to potentially get themselves in trouble, burn out an electric element, or cause a minor flood. It’s basically a marketing pitch telling your customers not to worry about such things because you’ve got them covered. That’s just as true when it comes to boiler maintenance, which also requires an experienced plumbing and HVAC contractor.

Keep Your Eyes Open

Maintenance starts before you even walk into a client’s home. There are things to look for immediately when you’re stepping out of the truck. Are the bricks and mortar on the chimney in good repair? Is the boiler and/or water heater sidewall vented? Is the sidewall vent far enough off the ground to clear snow cover? 

Sidewall intake and exhaust vents have to meet manufacturer requirements, plus they aren’t allowed to be under a window or over a doorway. Take the cover off the power venter to make sure the rodent screen is intact and that wasps or other critters haven’t taken up residence.

After you’ve entered the residence and made your proper introductions with the homeowner, check out the mechanical space. Do the appliances have enough combustion air? Sometimes the boiler and water heater get walled off during a remodeling project. For atmospherically fired boilers and water heaters, look for sooting or other signs of flame rollout. If the homeowner has installed new or high-powered kitchen and bathroom exhaust fans, they may be strong enough to create a negative pressure in the space.

Check the venting arrangement for both the boiler and the water heater. For a condensing boiler, the vent material may be Schedule 40 PVC, Schedule 40 CPVC, ABS, or polypropylene. For a non-condensing water heater, it could be single-wall galvanized steel. Mixing of vent materials is not allowed. If the boiler is sidewall vented and the water heater vents into the chimney, the water heater won’t draft properly unless there’s a chimney liner in place.

Water Leaks

Look around for water leaks from either piece of equipment, focusing on joints and elbows, the circulator, expansion tank and near-boiler piping. Check the floor to see if the boiler relief valve or the T&P relief valve on the water heater has discharged or is weeping. Test the T&P valve by lifting the lever and letting it drain into a bucket underneath the discharge piping. Make sure that the valve re-seats and doesn’t weep.

Boiler relief valves can be notorious for not reseating properly. State regulations can be spotty and testing recommendations from manufacturers vary from annually, every two years, and “as needed.” If the valve weeps, open it a second time to try to dislodge whatever is keeping it from seating. Don’t flip the lever unless you have a replacement valve in the truck. 

Sediment Problems

Flush out sediment in the water heater by draining 2 to 3 gallons of water via the drain valve at the bottom of the tank. If the homeowner has the gas valve cranked up to hot, let them know that hotter water creates more scale and sediment faster. If you can’t get the water to run clear on the first try, turn on the cold-water supply briefly to stir up sediment in the bottom of the tank and drain it a second time. If the water slows down to a trickle, it’s because a vacuum has formed in the tank. Pop open the T&P valve to let air into the tank to equalize the pressure. When flushing is finished, close the drain valve and the T&P valve.

Since the water is off and the tank is partially drained, now is a good time to check the condition of the anode rod. If the rod is less than 1/2-inch in diameter, it should be replaced.

If the space heat is coming from a boiler, a well-insulated indirect tank is always a good option for domestic hot water. Indirect tanks need to have their T&P valves tested and the tank drained annually, just like a conventional gas or electric water heater. The same goes for heat pump water heaters.

A wall-hung tankless water heater or a combination boiler will need to be serviced annually to remove lime scale. Water passages through a tankless unit tend to be smaller so they scale up more easily. The descaling operation is simple and takes about an hour and a half with some descaling fluid or simple white vinegar, some hoses, a bucket and a pump. Service valves conveniently located on the bottom of tankless water heaters make the job even easier.

Check the Fire Side

Always clean the fire side of the boiler’s heat exchanger. Remove the venting top, flue collector, draft inducer assembly, and heat exchanger baffles. Remove the burner tray. Use a hand-operated spray bottle filled with water and a wire brush to clean soot and loose scale from the underside of the heat exchanger. Don’t try to spray it with high-pressure water or air. Clean any fallen debris from the bottom of the unit. Check to make sure the burner ports and pilot assembly are clean before returning the burner tray to its original position. Reassemble the boiler in reverse order, making sure to replace the heat exchanger baffles.

An important step in any boiler service call is to verify operation of the safety controls, such as the high limit control to make sure it trips. Check all operating controls and safeties on the boiler, among them water temperature controls, automatic fill valve, pilot safety system, automatic gas valve, fan proving switch, the inducer/blower assembly and mechanical flue damper operation.

Space and water heating equipment needs regular maintenance to ensure that it’s trouble free. Tell your customers that you’re giving them peace of mind that their homes will be warm and their showers hot all winter long.

About the Author

Dustin Bowerman is director of corporate training and product support for Bradford White Corporation, a full-line manufacturer of residential, commercial and industrial products for water heating, space heating, combination heating and storage applications. For more information,


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