My 1983 Hunter 34 is a great boat. Over the years a few issues have crept up. One issue is that the head vent plugs. Our head is never used for solids, but most often, for used beer. Back pressure develops and bubbles back thru the head. Also, as pressure builds, it forces contents of the tank back into the head - thankfully not to overflow level but it is a concern. Salts appear to accumulate at the elbow inside the thru-hull. This is very difficult to reach and clear. I am thinking of reconfiguring the plumbing to make it easier to work on. The main complication is close proximity of the shower bilge hose thru-hull. Does anyone else have this problem? Or, has anyone solved this problem? I have a plan - sort of - but would appreciate any suggestions. We use Thetford (several ounces) liquid chemical as a holding tank treatment with each pump out.
head vent plugs
- Thread starter Mike F.
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Almost everyone has this problem...
The two most places for tank vent blockages are the thru-hull and the connection at the tank. Dust, pollen, spider webs etc, plus waste spilling out the vent when you're heeled build up in the thru-hull..dirt daubers LOVE to build nests in 'em. If there's a screen, it clogs up and also corrodes. Waste spilling into the vent when you're heeled can also build up in the vent fitting on the tank and that end of the hose. Using the vent as an "overflow" to let you know when the tank is full is another good way to block the vent. It doesn't matter if no solids or TP ever go into the tank (though it's silly to avoid it), salt and/or urine crystals build up--also contributing to a blockage in the thru-hull, resulting in a blockage. Your choice of tank treatment has nothing to do with it. I don't know what your plan is, but the right way to prevent it is to backflush the vent with clean water every time you pumpout and or wash the boat. It's VITAL that the tank vent never becomes blocked. If the toilet becomes increasingly harder to pump, begins to back up or "burp", stop using it immediately...continuing to use toilet against a blocked vent is a good way to take a bath in your tank contents when you open the deck fitting, or even burst a tank. The tank can't be pumped out or dumped against blocked vent either...the pump pulls a vacuum that prevents anything from being pulled out. A particularly strong pumpout can implode a tank. You might want to check out the link below...it's a "how to install, operate and maintain your toilet and tank 101" primer that focuses on how to prevent problems and cure the ones you neglected to prevent.
The two most places for tank vent blockages are the thru-hull and the connection at the tank. Dust, pollen, spider webs etc, plus waste spilling out the vent when you're heeled build up in the thru-hull..dirt daubers LOVE to build nests in 'em. If there's a screen, it clogs up and also corrodes. Waste spilling into the vent when you're heeled can also build up in the vent fitting on the tank and that end of the hose. Using the vent as an "overflow" to let you know when the tank is full is another good way to block the vent. It doesn't matter if no solids or TP ever go into the tank (though it's silly to avoid it), salt and/or urine crystals build up--also contributing to a blockage in the thru-hull, resulting in a blockage. Your choice of tank treatment has nothing to do with it. I don't know what your plan is, but the right way to prevent it is to backflush the vent with clean water every time you pumpout and or wash the boat. It's VITAL that the tank vent never becomes blocked. If the toilet becomes increasingly harder to pump, begins to back up or "burp", stop using it immediately...continuing to use toilet against a blocked vent is a good way to take a bath in your tank contents when you open the deck fitting, or even burst a tank. The tank can't be pumped out or dumped against blocked vent either...the pump pulls a vacuum that prevents anything from being pulled out. A particularly strong pumpout can implode a tank. You might want to check out the link below...it's a "how to install, operate and maintain your toilet and tank 101" primer that focuses on how to prevent problems and cure the ones you neglected to prevent.
Mike, depending upon the type of scupper...
that covers your tank vent through hull will depend upon how you keep the vent line clear. After every pump out I keep ours clear using city water pressure. I have a cone shaped nozzle that screws onto a garden hose pistol type sprayer. This nozzle fits over our boat's clam shell type scupper so that I can squirt water under pressure through the vent line. I've been doing this ever since I unclogged our vent line left by the PO. Our vent line remains clear and trouble free four years later. Another skipper on this site uses a drain plunger. He removed the wooden handle from the rubber plunger and fitted a garden hose nozzle in its place after drilling a hole for the water to flow. Great idea. That way you can use pressurized water to force any material back into the tank. Terry
that covers your tank vent through hull will depend upon how you keep the vent line clear. After every pump out I keep ours clear using city water pressure. I have a cone shaped nozzle that screws onto a garden hose pistol type sprayer. This nozzle fits over our boat's clam shell type scupper so that I can squirt water under pressure through the vent line. I've been doing this ever since I unclogged our vent line left by the PO. Our vent line remains clear and trouble free four years later. Another skipper on this site uses a drain plunger. He removed the wooden handle from the rubber plunger and fitted a garden hose nozzle in its place after drilling a hole for the water to flow. Great idea. That way you can use pressurized water to force any material back into the tank. Terry
Mike, depending upon the type of scupper...
that covers your tank vent through hull will depend upon how you keep the vent line clear. After every pump out I keep ours clear using city water pressure. I have a cone shaped nozzle that screws onto a garden hose pistol type sprayer. This nozzle fits over our boat's clam shell type scupper so that I can squirt water under pressure through the vent line. I've been doing this ever since I unclogged our vent line left by the PO. Our vent line remains clear and trouble free four years later. Another skipper on this site uses a drain plunger. He removed the wooden handle from the rubber plunger and fitted a garden hose nozzle in its place after drilling a hole for the water to flow. Great idea. That way you can use pressurized water to force any material back into the tank. Terry
that covers your tank vent through hull will depend upon how you keep the vent line clear. After every pump out I keep ours clear using city water pressure. I have a cone shaped nozzle that screws onto a garden hose pistol type sprayer. This nozzle fits over our boat's clam shell type scupper so that I can squirt water under pressure through the vent line. I've been doing this ever since I unclogged our vent line left by the PO. Our vent line remains clear and trouble free four years later. Another skipper on this site uses a drain plunger. He removed the wooden handle from the rubber plunger and fitted a garden hose nozzle in its place after drilling a hole for the water to flow. Great idea. That way you can use pressurized water to force any material back into the tank. Terry
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