Roberts Gorden 175 - Manual (Page 17)

SECTION 5: N ATIONAL S TANDARDS AND A PPLICABLE C ODES
9 of 51
5.6 High Altitude
These heaters are approved (without modifications)
for installations up to 2000' (610 m) in US and
Canada. Heaters installed above 2000' (610 m)
must be de-rated. For installations above 2000' (610
m) in US, consult factory for information on burner
de-rating. For installations from 2000' (610 m) to
4500' (1370m) in Canada, high altitude conversion
kits are available. Heaters installed over 4500'
(1370 m) in Canada are not approved and must be
approved by the local or provincial authority.