Washington · Boilers

The boiler inspection rules in force in Washington now.

Ch. 70.79 RCW + ch. 296-104 WAC; inspection frequencies in WAC 296-104-100 as amended by WSR 26-18-075 (filed Sep 1, 2026, effective Oct 2, 2026). Enforced by L&I Boiler and Pressure Vessel program issues certificates of inspection; inspections by L&I inspectors or commissioned insurance-company/operating-company special inspectors (RCW 70.79.130). Checked on the primary source; the state record was last reviewed 2026-11-12.

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Boilers in Washington

Checked on the source

In force

Ch. 70.79 RCW + ch. 296-104 WAC; inspection frequencies in WAC 296-104-100 as amended by WSR 26-18-075 (filed Sep 1, 2026, effective Oct 2, 2026)

WAC 296-104-100: power boilers external and internal annually (owner-user programs may extend internals to seven years or half remaining life); steam heating boilers biennially; hot water heating boilers external biennially, internal every fourth year; water heaters and hot water supply boilers external biennially; unfired pressure vessels biennially, internal only if subject to corrosion.

Source: primary document

Who enforces it

L&I Boiler and Pressure Vessel program issues certificates of inspection; inspections by L&I inspectors or commissioned insurance-company/operating-company special inspectors (RCW 70.79.130)

Statewide layer. County and city amendments sit on top; confirm the local office for the address.

What changes next

Rulemaking pending

WSR 26-18-075 in force Oct 2, 2026 (history note re-read Oct 19, 2026); new operation section WAC 296-104-450 takes effect Apr 2, 2027 per the WSR 26-12-068 proposal (adopted text not re-read)

The federal layer

There is no federal boiler certificate; the state program below is the whole obligation, with the ASME Boiler and Pressure Vessel Code and the National Board Inspection Code as the referenced standards.

What a building has to do

1 recurring duties

These apply when the building has the equipment or fits the type named. The frequency is the standard one; your local official can set a stricter one, so confirm it for the address.

Annual

Boiler: certificate inspection per state programState boiler law · State boiler inspection program · Not yet checked line by line against the source.

Questions about the boiler inspection rules in Washington

Which boiler inspection rules apply in Washington today?

Ch. 70.79 RCW + ch. 296-104 WAC; inspection frequencies in WAC 296-104-100 as amended by WSR 26-18-075 (filed Sep 1, 2026, effective Oct 2, 2026). WAC 296-104-100: power boilers external and internal annually (owner-user programs may extend internals to seven years or half remaining life); steam heating boilers biennially; hot water heating boilers external biennially, internal every fourth year; water heaters and hot water supply boilers external biennially; unfired pressure vessels biennially, internal only if subject to corrosion.

Who enforces the boiler inspection rules in Washington?

L&I Boiler and Pressure Vessel program issues certificates of inspection; inspections by L&I inspectors or commissioned insurance-company/operating-company special inspectors (RCW 70.79.130).

What changes next for the boiler inspection rules in Washington?

Rulemaking pending. WSR 26-18-075 in force Oct 2, 2026 (history note re-read Oct 19, 2026); new operation section WAC 296-104-450 takes effect Apr 2, 2027 per the WSR 26-12-068 proposal (adopted text not re-read)