Cabin Water System Questions

CabinNick · January 13, 2017, 11:14:05 PM

I am starting to come up with a plan for the water system for our 20x30 1.5 story cabin. I am researching all my options; thought folks on the forum could probably point me in the right direction from all your experiences.

Background info:
•   Water will come from a 1000 gallon buried cistern supplied by a spring
•   Would like to use the cabin water year-round but will not heat it full time in the winter – i.e. will need a system we can flush the water out of each time we leave in the winter.
•   Will have a solar power system with some form of backup generator – system will be sized for lights, cell/computer charging, small kitchen appliances, ceiling fan, etc.
•   Water consumptions will be kitchen sink, a full bath (shower only) and a half bath on second floor. No clothes or dish washer.
•   We will have propane hot water, stove, fridge. Not interested in solar hot water due to the year round need for hot water.
•   No basement; just a crawlspace with perimeter foundation.

Questions:

1)   I have two options – cistern adjacent to the cabin (4 foot greater elevation) and use some form of pump to generate pressure or spend $4,000 more and place the cistern a long distance uphill from the cabin and have about 30-35 psi of gravity flow pressure. What would you do?

2)   If I decide to go with having a mechanically pressurized system, should I be looking at a pump with pressure tank or is an inline RV style pump an option?

3)   Heating hot water with propane – should I be looking at tankless or a traditional hot water heater?

Thank you for any advice to help get me started in the right direction.

Mike 870 · January 14, 2017, 09:13:46 AM

Here are some of my in progress system. Based off RV water systems. 300 gallon tank buried under my foundation, filled by truck tank. 12v RV pump with purge valves for winterizing. Will have a pressure tank inline. I could have buried mine uphill like your considering, but I would have had to trench through the woods and build some sort of rain collection roof or a trail to the tank. Seemed like a lot of work, and I can easily do it after the fact if need be, but I couldnt add a tank under the foundation after the fact.

January 14, 2017, 10:42:35 AM

I made a small system like this in one of my work trucks. The RV pump was fine for my purposes. I had a heated shower and sink.

ChugiakTinkerer · January 14, 2017, 01:01:31 PM

I'm still in the conceptual design stage for our remote cabin, but I'm planning on having it plumbed for summer use. Still to determine feasibility but I'm hoping I can have a sand-point driven well that will fill the bill in place of the cistern.

I will pump water from the wellhead to a storage tank on the second floor of the cabin. This along with a 12V RV on-demand water pump should give me enough pressure and flow to be functional. Water needs will be limited to kitchen and the occasional hot shower, if I can make that work. I don't think a pressure tank will be needed. The system will be purged in the fall and left idle over the winter. Temperatures are too low to even contemplate use in the winter.

If you update your profile to indicate approximate location it will help folks understand your needs a little better.

Mike 870 · January 14, 2017, 04:26:52 PM

Also, these are great for easy winterizing. You can get different sizes, connection type etc. These happen to be threaded. http://www.supplyhouse.com/Webstone-40613W-3-4-Pro-Pal-Full-Port-Forged-Brass-Ball-Valve-w-Hi-Flow-Hose-Drain-Reversible-Handle-Lead-Free

January 14, 2017, 08:35:17 PM

I have had problems with RV pumps freezing even when run dry. I disconnected the pump and ran it until all of the water seemed to be out of the lines. Some water stayed in the pump and, after freezing, caused the pump to leak at the gaskets. Water would drip from the pump, but, more importantly, the pump would not easily lift water when started dry. I resealed the pump and I now remove the pump and store it where it won't freeze. RV antifreeze in the pump would probably prevent this and it might not happen if the pump is blown out with compressed air, but it isn't that hard to just remove the pump.

DaveOrr · January 14, 2017, 10:55:05 PM

Quote from: wgiles on January 14, 2017, 08:35:17 PM
I have had problems with RV pumps freezing even when run dry. I disconnected the pump and ran it until all of the water seemed to be out of the lines. Some water stayed in the pump and, after freezing, caused the pump to leak at the gaskets. Water would drip from the pump, but, more importantly, the pump would not easily lift water when started dry. I resealed the pump and I now remove the pump and store it where it won't freeze. RV antifreeze in the pump would probably prevent this and it might not happen if the pump is blown out with compressed air, but it isn't that hard to just remove the pump.

I plan on using a 24V DC RV pump that they use in the big class A bus type RV's.
It will be installed with quick connectors for easy removal come the end of the season.
Most just use buckets for water in the winter up in these parts.
Wouldn't want to have to winterize the system every time I use it in the cold months.

CabinNick · January 15, 2017, 12:01:17 AM

Thanks for the feedback everyone. I updated my profile to show where I am at - mountains of NE Oregon - so I am dealing with very deep snow and fairly cold winter temps. We just set some records last week with lows around -30 but a typical winter doesn't get more than a few degrees below zero at night more than a few times.

I am going back and forth on winterizing the cabin and not using running water in the winter vs. setting the system up where we can use running water in the winter and the flush the system when we leave and put antifreeze in all the traps. Seems like it would be a lot easier to do if we had gravity flow pressure vs. a pump. A friend with a cabin nearby does this successfully but they are on gravity pressure and don't have a hot water heater.

cbc58 · January 15, 2017, 09:09:10 AM

Some great information here. What would be the benefit of burying the tank under the cabin ? What happens if you have to access it for some reason ?

January 15, 2017, 12:12:09 PM

I wanted it under the cabin so that I could have my water lines, pump, etc in conditioned space without having a long trench. It's also nice for the pump to be close since it's 12v. I'll be building an insulated skirt around a 8x4 section above the tank. If i have to access it I can do so through an access door on the side of the foundation. If the tank needs minor repairs I can reach inside it. If it it ever has a major failure, It will become a broken tank in the ground...