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Old 06-09-2024, 10:53 AM   #1
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Join Date: Jul 2023
Location: New Mexico
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JDuvall is an unknown quantity at this point
Holding tanks

Hi everyone! I have an 85 Sunline, T1550. It's a small guy. I'm wondering if you know how much the black water tank can hold in relation to fresh water? How many times can we fill up fresh water before emptying it? Thank you!

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Old 06-10-2024, 06:48 AM   #2
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Hi JDuvall,

By the 1985 brochure, the T1550 has,

18-gallon freshwater approximate system, including tank and water lines. The water heater was optional on your model, and we are unsure if you have one. If you do have one, the water heater commonly used adds six more gallons to the entire system. You cannot pump the last 6 gallons in the heater, only what is in the fresh tank. Between water lines and what the pump can pump and not lose prime, you may have about 12 to 15 gallons of usable water from a full fresh tank.

The black tank is listed as 10 gallons.

The grey tank is listed as 21 gallons.

You can use all fresh water in the sinks and the toilet, so plan accordingly on how much you can use for the toilet.

In case you did not know, this information from the brochure is in our FILES section. When logged in, look at the top of the forum for FILES. Click it and go to Brochures, scroll to your year, and download a copy. There is also a lot of other good information in the files section.

How many fill-ups of the freshwater tank can you have before you fill the black tank? That is hard to nail down as you split the fresh water to the sinks, and some folks flush longer than others. Then, how often during the day do you go? If you use a flashlight, open the flush valve on the toilet and look down to see how full it is. You will learn over time how many days you can go before having to dump the black tank. This comes in time; it's not that hard once you have been through it before.

I hope this helps. Have fun with your new Sunny!

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Prior Sunlines: 2004 T2499 - Fern Blue
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black water, fresh water, holdling tanks

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