How Big Is The Xtreme Heaters RV Basement And Boat Bilge Heater For Tight Engine Compartment?

Updated 10/16/2025 | Published 09/30/2025

Question:

How big is the 800W heater physically? I need to check fit in a tight engine compartment.

asked by: Steve

Expert Reply:

Steve, the heater body of the # XH27FR is about 8” long, 5-1/8” tall, and 3-1/2” deep/wide. With the mounting feet, length is just over 9”, and with the quick-release bracket, add about another inch in overall length. The bracket itself is 10-7/8” long by 4-3/4” wide. It’s a compact footprint for the output, which makes it popular for cruisers and houseboats.

Where in the compartment are you looking to place it - low and centered, or tucked outboard?

expert reply by: Andrew N

Steve

10/16/2025

Thanks, Andrew. I’m thinking of mounting it on the port side, right next to one of my engines. Just worried it might be too tight around the fuel lines and wiring harnesses.

Carl

10/16/2025

@Steve Steve, I’ve got mine mounted outboard on a twin-engine Bayliner. space was tight too. I just used standoff spacers to keep the heater about half an inch off the bulkhead and routed the wiring up and away. Works great and stays clear of the fuel lines. The quick-release bracket made it way easier to line up.