Water Heater Installation in Fort Collins and Loveland

What a code-compliant water heater installation includes

Colorado’s plumbing and fuel gas codes build on the 2024 International Residential Code (IRC), and Fort Collins, Loveland, Larimer County and Weld County enforce 2024 editions. These are the main water heater code requirements on a tank installation.

Expansion tank installation, where your system needs one

The IRC requires thermal expansion control where a pressure-reducing valve (P2903.4.1) or a check valve or backflow preventer (P2903.4.2) stops heated water from expanding back toward the main. Not every home has those devices, so we check before quoting a tank. Colorado’s plumbing code and Larimer County add that the tank must be supported as its manufacturer specifies, not hung from its pipes. See do I need a water heater expansion tank.

T&P relief valve and discharge pipe

Every tank needs a temperature and pressure (T&P) relief valve that opens at no more than 150 psi or 210°F, with no shutoff or check valve on either side (IRC P2804). Its discharge pipe must be full size, drain downhill with no trap, valve or tee, and end, unthreaded, no more than 6 inches above the floor, pan or drain receptor.

Colorado’s plumbing code now also requires relief valve discharge to be piped to a drain or outdoors, but replacements of existing water heaters are exempt, and Fort Collins adopted the same rule. Never cap or plug a T&P valve.

Drain pan

Where a leak would cause damage, the tank sits in a pan at least 1½ inches deep with a drain of at least ¾ inch to a receptor, or outdoors 6 to 24 inches above grade (IRC P2801.5). On a replacement, no pan drain is required where none existed, and Colorado and Fort Collins exempt replacements of heaters that had no pan under the code at the time.

Gas shutoff and sediment trap

Gas models need a shutoff valve in the same room, within 6 feet of the heater and upstream of the connector (IRC G2420.5.1), and a sediment trap downstream of it, as close to the gas inlet as practical (G2419.4).

Venting and the plastic vent pressure test

Plastic vent pipe is allowed only when the heater is listed for it and its instructions name the pipe material (G2427.4.1). Colorado’s fuel gas code requires new plastic exhaust pipe on a gas water heater to be tested at 5 psi of air, or a 10-foot water column, at inspection before it is connected.

Larimer County requires vent terminals at least 12 inches above the expected snow level and 22 inches above grade, and Fort Collins requires 22 inches above grade. Loveland requires an exhaust test certification for plastic venting and bans cellular core pipe on direct-vent exhaust, even existing pipe. Windsor prohibits cellular core PVC for water heater exhaust.

Combustion air

By the IRC’s standard method, a fuel-burning heater’s space needs at least 50 cubic feet of indoor air per 1,000 Btu/h of appliance input (G2407.5.1), so 40,000 Btu/h needs 2,000 cubic feet. A small closet usually falls short and needs combustion air openings or ducts, which Fort Collins requires to carry a carbon monoxide warning label.

Water heater in a garage: the 18-inch rule

In a garage, a water heater’s ignition source must be at least 18 inches above the floor unless the heater is listed as flammable vapor ignition resistant (IRC P2801.6, G2408.2). Rooms that open directly into the garage and are not living space count as garage, and Larimer County extends the rule to barns and similar utility spaces.

Altitude setup

The fuel gas code requires the volume of gas supplied to be adjusted for altitude above 2,000 feet (IFGC 402.2), and USGS elevations put Fort Collins at 5,004 feet, Loveland at 4,986 and Estes Park at 7,530. How a heater handles altitude depends on the model: one Bradford White power vent manual certifies its heater to 10,100 feet without modification, while another calls for a high-altitude kit above 2,500 feet because the blower moves less air as air density drops. We set each heater up from its manual and your home’s elevation.

CO alarms on fuel-fired replacements

Loveland’s permit application quotes Colorado law: in a single-family home with fuel-fired appliances or an attached garage, a permitted fuel-fired appliance replacement requires a working carbon monoxide alarm within 15 feet of each sleeping room entrance. Weld County’s express permit requires smoke and CO detectors when fuel-fired appliances are replaced or installed.

The rest of the checklist

The code also requires a full-open cold-water shutoff at or near the heater (P2903.10.2) and a drain valve of at least ¾ inch (P2801.1). Earthquake straps are not required by the IRC here: Fort Collins, Larimer County, unincorporated Weld County and Windsor are in Seismic Design Category B, and the anchoring rule (P2801.7) applies only in categories D0 through D2 and to townhouses in C.

What a complete written installation quote includes

Quotes are only comparable when they list the same items. Ours spells out:

• Heater make and model, capacity, first-hour rating and UEF
• Fuel and vent type
• Labor
• Permit and inspection
• Expansion tank, if your system requires one
• Drain pan, if required
• T&P discharge piping
• Gas shutoff, flexible connector and sediment trap
• Venting changes and the vent pressure test
• Altitude setup
• CO alarms, where your jurisdiction requires them
• Haul-away of the old tank
• Any other code upgrades

Every job is done by licensed plumbers and covered by liability insurance, and you get the itemized quote before work starts. If a repair makes more sense, we will tell you; see water heater repair. For what drives the price, see our water heater replacement cost guide.

Colorado’s 2026 low-NOx rule for gas water heaters

Since January 1, 2026, Colorado’s HB23-1161 has barred the sale of new gas water heaters that emit more than 10 nanograms of NOx per joule (units rated up to 75,000 Btu/h, or with power assist) or 14 ng/J (larger units under 2 million Btu/h). ENERGY STAR certified models are deemed to comply, and heaters already in Colorado inventory before 2026 can still be sold. Since August 12, 2026, SB26-002 exempts propane models until January 1, 2031, and electric and heat pump models are outside the rule. More in our guide to the Colorado low NOx water heater law.