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Tankless water heater installation in Castle Rock

This is the Town's permit path for a tankless heater, not Aurora's. The residential permit page says tankless units require plan review. You provide the manufacturer's specification sheet and gas piping load calculations. A storage-tank heater is listed separately and may not need that review.

What to hand over

The sheet for the model you are buying, and the gas-load math for the house, not a sentence that says the old tank was smaller. Building-code amendments took effect June 30, 2026. Ask the counter if a packet drawn earlier still matches. The building phone on that page is 720-733-3527. It is the Town's. This guide's own referral number is not published. The town hub is Castle Rock. The general conversion questions, vent and condensate, stay on tankless installation and should be answered in addition to the Town's packet, not instead of it.

Plumber tightening copper water supply pipes with wrench — **Supply line connections:** High-temperature copper and brass joints handle incoming municipal pressure and thermal expansion safely.

Water line is a different FAQ

If the job also touches the water service, Town water customers are told the Town maintains the line to the property-line connection and owns the curb stop. Do not shut that street valve. That rule is not part of the gas-load sheet, and it is not Aurora's. A quote that changes both the heater and the yard pipe should say so.

Plumber adjusting water and gas pipe fittings with adjustable wrench — **Piping and gas load adjustment:** Checking pipe pitch, gas supply sizing, and shutoff valves ensures safe water heater operation.

No savings percentage and no price are printed here. No contractor is dispatched.

Questions to settle first

What does Castle Rock require that a tank swap might not?

Plan review, the manufacturer specification sheet, and gas piping load calculations. The Town's permit page calls tankless out. A storage-tank water heater may avoid that review. Do not submit the tankless unit on a tank assumption. Ask them to write that limit into the quote before you compare it with another company.

Can I use Aurora's same-day inspection instead?

No. Aurora's sentence is for Aurora, and even there it is not a guarantee. Castle Rock's counter is 720-733-3527 on the permit page. Call that office about the review. It is not this website. Ask them to write that limit into the quote before you compare it with another company.

Do the 2026 codes matter?

The Town says the adopted amendments took effect June 30, 2026. An older checklist from another metro city is the wrong attachment. Ask if your submittal matches the current packet. Ask them to write that limit into the quote before you compare it with another company.

Does the gas calculation include a water-line repair?

Only if you are also changing water piping. The calculation is the heater's fuel demand. The curb-stop rule is a separate Town FAQ. Keep the two scopes visible on the quote. Ask them to write that limit into the quote before you compare it with another company.

Plumbing fittings, shutoff valves, and equipment layout — **Safety valves and relief components:** Temperature and pressure relief valves and expansion tanks protect residential heating tanks from over-pressurization.