HEAT EX CHANGER PENCIL ANODE

Aug 11, 2011
857
O'day 30 313 Georgetown MD
What would be the normal replacement period for the pencil anode in the heat exchanger? Also, and this might sound silly, but is there an anode in the engine that needs to be periodically changed? I have a Universal M-20 diesel.
 
Oct 22, 2014
20,995
CAL 35 Cruiser #21 moored EVERETT WA
I do not know a time certain period. It depends on a number of variables that in part are based on your environment.

I’d suggest you start a log. Install a new pencil anode and record the date. First check at 3 months, record the hours of usage and state of anode. Decide if 3 months is right length of time. Repeat until need to replace anode. :biggrin:
 
Feb 26, 2004
22,760
Catalina 34 224 Maple Bay, BC, Canada
I have a Universal
The Universals only pencil zincs are in the the HXs. John's right, start with three months checks, build up from there. I got 3-4 months in SF for 18 years, now get 6 months in my current location.
 
Dec 27, 2012
587
Precision Precision 28 St Augustine
My boating season is from April through October. I start the season with a new one and replace again mid season.
 
Apr 5, 2009
2,774
Catalina '88 C30 tr/bs Oak Harbor, WA
Mine lasts about 9 months and I have the system drained about 3 months for winterizing so I use one per year.
 
Aug 11, 2011
857
O'day 30 313 Georgetown MD
Took mine out. Minimal wear on the sacrificial anode. I replaced it for the season. My boat sits in fresh water as its on the sassafras river, but my sailing water is brackish. That would account for its slow degrading. My Marina had them on sale for the startup season, so I bought a few.
 
Oct 22, 2014
20,995
CAL 35 Cruiser #21 moored EVERETT WA
An on sale purchase of a defensive tool to keep your boat working at her best... seems like an excellent idea to me. :clap:
 
Oct 22, 2014
20,995
CAL 35 Cruiser #21 moored EVERETT WA
You may have all your corrosion causing electrical circuits working properly thus the apparent “minimal wear”. Good on you.

If the type of water is the issue you may want to select an alternative metal to zinc.

Attached find a comparison of the three commonly used metals. Maybe an aluminum anode would better serve you.
 

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