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Oil or Gas Boiler Replacement

Installed correctly, new oil or gas boiler can cut utility expenses while improving comfort.

Systems for heating and cooling your home cost more money and use more energy than any other system in your home—typically over 50% of your utility bill. High-efficiency sealed-combustion direct-vent oil and gas boilers have efficiencies exceeding 90% and improve safety by drawing combustion air from outside instead of indoors and exhausting emissions through sealed flues. However, a quality installation is integral to a well-performing system. Nearly half of all heating and cooling systems in U.S. homes are not installed to the manufacturers’ instructions and perform below rated capacity and efficiency.

Checklist

This U.S. Department of Energy checklist includes important specifications that can contribute to a complete and quality installation. All work shall comply with these specifications, all relevant codes and standards, and all manufacturer installation instructions. The contractor shall check each box on the checklist below and sign and date at the bottom to certify the work is completed.

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Preparation


All accessible piping, radiators, and other components shall be inspected for damage or asbestos, and any observed problems shall be reported to the homeowner with recommendations for remediation before proceeding with the work. Alternately, in the case of hydro coil forced-air heating systems, the duct system shall be inspected, and any damaged, disconnected, undersized, unsupported, or excessively long ducts shall be repaired or replaced.

Equipment shall be selected and sized in accordance with the Air-Conditioning Contractors of America (ACCA) manuals J and S.

Installation


An ENERGY STAR-certified, high-efficiency, sealed-combustion, direct-vent boiler shall be installed.

The boiler shall be installed in accordance with the ANSI/ACCA Standard 5 HVAC Quality Installation Specification.

For improved efficiency, the boiler shall include a multi-stage or modulating burner with adjustable output to better match heating loads, reduce the number of on-off cycles (and cycling losses), and allow operation for longer hours at lower firing rates.

The boiler shall be equipped with electronic controllers, which can increase equipment life, improve boiler efficiency, and enhance comfort by adjusting boiler water temperature, creating time-delay relays, performing automatic post-purge, preventing warm weather boiler operation, controlling the position of mixing valves, and controlling pump speeds.

The condensate line shall drain to a sewer or to outdoors. If condensate is drained to outdoors then the drain pipe shall be protected from freezing with either insulation or heat tape. Also, a drain pan shall be installed under the boiler as a backup measure.

An outdoor reset sensor shall be placed away from any exhaust vents including kitchen, bath, dryer, and mechanical system vents and it shall not be in direct sunlight during any portion of the day. For condensing boilers, an outdoor reset control shall be installed matching system output to actual load and a recommendation shall be provided to homeowners to not use a night-time temperature setback strategy. Settings for the boiler reset curve and flow rates shall be selected to optimize the performance of the system and to ensure that the return temperatures are low enough to promote condensing.

If installation of a new direct-vent sealed-combustion boiler results in a vacated entry point in the chimney, the hole in the chimney wall shall be sealed.

The warm weather shutoff shall be verified to be set at a high enough temperature to prevent no-heat situations during the swing seasons.

Commissioning


A minimum of a 20°F temperature differential shall be maintained between the supply and return temperatures under design conditions.

The temperature setting on the boiler reset curve shall be below the boiler’s high limit setting.

The warm weather shutoff shall be verified to be set at a high enough temperature to prevent no-heat situations during the swing seasons.

Where present, the gas line shall be tested for leaks and a combustion safety test shall be performed after installation is complete.

If installing a direct-vent boiler results in an orphaned water heater still connected to an existing vent or chimney that may now have inadequate draft to remove the water heater combustion emissions, the contractor shall inform the homeowner of necessary remediation steps (e.g., installing a chimney liner) to provide proper venting and code compliance.
Oil or Gas Boiler Replacement

Tips to Sell Quality Installed Home Improvements

Home Improvement Expert is a valuable tool for organizations committed to quality installed work. The following tips help optimize the value of this tool when selling home improvements:

Trust Matters: Inform homeowners how your work conforms to this world-class expert guidance. Recommend they visit the DOE website as evidence these are indeed official best practices.

Knowledge Matters: Take advantage of the Building America Solution Center as a resource for becoming an expert on these projects.

Clarity Matters: Tell prospective clients to contrast your expert-recommended best practices with other contractors.

Value Matters: Advise prospective clients to insist other bids also include these checklists to ensure equivalent quality work.

Message Matters: Showcase on your website and marketing materials that your company uses the highest quality best practices specified on HIE Checklists.

Experiences Matter: Provide visual evidence contrasting the difference between poor and high quality work such as infrared images; pre- and post-energy bills; short and long warranties; and simple charts and graphics depicting performance advantages.

Related Guides

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Pre-Retrofit Assessment of Existing HVAC Systems

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Information guide describing options to consider when retrofitting or upgrading a home's HVAC system.
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Gas-Fired Boilers

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Guide describing gas-fired boilers and hot water heat distribution systems used for home heating.
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Oil-Fired Boilers

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Guide describing oil-fired boilers and hot water heat distribution systems used for home heating.
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Condensing Boilers

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Guide describing condensing boilers and hot water heat distribution systems used for home heating.

Disclaimer

This content is a work created with funding provided by the United States Department of Energy under Contract no DE-AC05-076RL01830 for the operation of Pacific Northwest National Laboratory. The information and guidance provided by Pacific Northwest National Laboratory (PNNL) in the content are intended solely for educational purposes only and do not constitute formal training or certification. It is provided with the explicit understanding that neither the United States Government nor the United States Department of Energy, nor the Contractor, nor any or their employees, nor any jurisdiction or organization that has cooperated in the development of these materials, makes any warranty, express or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or usefulness or any information, apparatus, product, software, or process disclosed, or represents that its use would not infringe privately owned rights. Reference herein to any specific commercial product, process, or service by trade name, trademark, manufacturer, or otherwise does not constitute or imply its endorsement, recommendation, or favoring by the United States Government or any agency thereof, or Battelle Memorial Institute. The views and opinions of authors expressed herein do not necessarily state or reflect those of the United States Government or any agency thereof. Viewers assumes full responsibility for all actions that they may take from information provided in this content including ensuring the safety, code compliance, and proper functionality of any products they choose to install. Installation and use of such products should be performed in accordance with local regulations and manufacturer instructions.