DST800 flap

[tomsp]

I installed the depth, speed, temp DST800 in March 2017. Boat was back in the water Late June 2017 and has remained so since. When I'm not sailing I remove the transducer and insert the blank. When I sail, 2 days a week, I take out the blank and insert the transducer - in SF Bay leaving the transducer in will see it clog up with critters in no time (less than a week). Removing the transducer and blank have been effortless with very little water ingress. Friday I went sailing - going out for a couple of days- at dock I tried to remove the blank to insert the transducer and the blank was really difficult to take out - when it did come out water really gushed up. Putting in the transducer was difficult too - it did t seem to want to seat correctly and water kept oozing in. I re-set it in the [censored] twice and finally water stopped and all was good. Sunday I removed the transducer- came out easy- but water just gushed in again as if the flapper was not there. Without hauling the boat to check is there a way to see what's happening down there?

[Chuck - Raymarine - Moderator]

Welcome to the Raymarine Forum Tom,

The housing of flapper valve equipped transducer housing feature a hinge located slightly lower down the throat of the transducer's seat. The upper portion of the plastic valve is connected to the aforementioned hinge. The plastic valve is pressured inward by a length of sprung steel. The pressure of the water then forces the valve further inward and slightly upward against the valve's seat. Were one to apply a suction cup or other sealing device over the outboard face of the transducer, then the transducer may be extracted from the housing to test the valve for freedom of movement and to verify the operation of the aforementioned spring.

[tomsp]

Ok I used a plumber plunger to suction over the hull area and pulled the blank plug - no flapper inside. Is there a part number for just the housing with flapper and not for the whole unit- transducer and housing?

Thank you.

[Chuck - Raymarine - Moderator]

Tom,

It is recommended that Gemeco, Inc. (Airmar’s US distributor (803 693 0777)) (the transducer's manufacturer) be contacted for transducer parts. They can also assist with positive identification of the transducer.