As part of their regular maintenance process, contractors suggest ways in which homeowners can save energy. Existing boilers may benefit from outdoor reset controls — if not already equipped — and programmable thermostats can also reduce energy consumption. These two measures alone could save 15-20 percent yearly from the fuel bill.
Outdoor reset control can help save money, because it changes the temperature of the supply water as the outdoor temperature gets cooler or warmer. Evaluating the installation of more efficient pumps could potentially help with electrical consumption, as well the amount saved would depend on the application.
One type of reset control that may help improve the energy performance of older, noncondensing, non-modulating on-off boilers is the FuelMizer from Taco Comfort Solutions. This outdoor reset switching relay is both a boiler reset control and switching relay and is designed to regulate the supply water temperature of a single boiler based on the outdoor temperature. With reduced supply water temperatures, substantial energy savings is achieved.
Typical energy savings is about 14 percent, though some customers have experienced up to 30 percent reductions in energy use once the FuelMizer is installed. The device is incredibly easy to install and set. Simply disconnect line voltage to the boiler, bring it into one side of the control, and bring it out the other side and back into the boiler. That’s it. Setup couldn’t be simpler — just dial it to the design temp, and that’s it. At design conditions, the default assumes the need for 180°F.
Of course, there is a certain point at which boiler efficiency can no longer be sustained or improved and replacement becomes necessary — particularly if the boiler has not been maintained properly. Poorly maintained boilers operated with very hard water can result in drastically reduced efficiency and performance due to hard water residue in a boiler heat exchanger and other components. Depending on the situation, it may be more cost-effective to replace the unit.
And once that old boiler is replaced with a shiny, new, energy-efficient one, contractors have yet another opportunity to talk about the need for regular boiler maintenance. After spending thousands of dollars for a new unit, homeowners may be more willing to keep their investment working properly.
9 BOILER MAINTENANCE STEPS
Residential boilers should be serviced annually
Modulating-condensing boilers need to be checked more frequently. We take the following steps when inspecting a modulating-condensing boilers:
- When doing a routine inspection of the burner, we first remove the burner itself. This allows access to inspect the combustion chamber and see if any combustion byproducts have accumulated. Outside the burner chamber, we check fans and blowers for buildup of dirt on the fins. If the boiler is equipped with filters on the makeup air, clean or replace them.
- Checking all of the safeties and controls, including the time it takes to light the boiler after each shutoff. Some boilers and controls require more time because of the post- and pre-purge and ignition timing.
- With an atmospheric burner, it may be appropriate to allow the pilot to light but not to fire the main burners. We check the pilot flame and compare the inlet gas pressure to the factory recommendations.
- Verify that all the electrical connections are secure. Check all wiring for overheating. Hardening or melting of wiring or connections is a sign of a more serious problem, such as chambers firing too hot.
- Check the flue passages. These indicate whether the boiler is burning properly. If there’s soot in the flue passage, the system may be running rich or have insufficient combustion air. If there’s moisture in the vent pipe, the system is running too cool.
- Inspect the vent pipe. We look for any white, powdery residue that may be left behind from condensation taking place in the vent. Condensate is extremely acidic and can eat through the vent pipe material. Be sure to maintain stack temperatures above manufacturer minimums to prevent this.
- Check all flame-sensing rods. We also, examine the spark rods to ensure they’re properly gapped. Always check the ceramic retainer that holds each of these to be sure there are no hairline fractures.
- Check the condensate drain. Is the line free and is flow unobstructed? Is there sufficient acid neutralizer media in place?
- When finished with the inspections and cleaning, we make sure to fire the boiler and run through a proper combustion setup procedure. Is there proper combustion? We use a properly calibrated combustion analyzer to check the CO2 before leaving the job.
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