Northern Lights — Zinc Electrode Service (SP-18)
Maintenance · Heat exchanger zinc electrodes
From a Northern Lights operator's manual covering: M40C3, M944, OM944T3. Check it applies to your exact model before use.
Applies to: Northern Lights M40C3, Northern Lights M944
Before you start
- Do not use thread sealant on the zinc holders.
Procedure
- Check zinc electrode every 250 hours; more often in warm saltwater or where electrolysis is a problem.
- Remove the zinc holder from the bottom of the exchanger to drain raw water.
- Scrape or steel brush the electrode clean; replace if more than 50% is corroded away.
- Reinstall zinc holders with clean threads for good metal-to-metal contact.
- Refill the cooling system, start engine and check for leaks.
Tools required
- Scraper or steel brush Amazon
Tool links are Amazon searches (affiliate links); manufacturer special tools may only be available from a dealer.
Full service-parts list: Northern Lights M40C3 →, Northern Lights M944 →
Source: Northern Lights operator's manual. Steps and values are as documented; always cross-check against the official manual and any later revisions for your exact serial number before servicing.