Thursday, January 20, 2011

Valve job

I am at the Wal-Mart in Fort Pierce, Florida (map). While many if not most Florida Wal-Mart stores do not permit overnight parking, usually due to local ordinance, this one does, and I counted at least another dozen rigs here last night. I shunned the "RV ghetto" in favor of the part of the lot where the trucks park. I had to listen to a reefer all night, but I had fewer looky-loos, and it was darker. I also wanted to distance myself from the group of RVers from several rigs who set their lawn chairs up in a circle in the parking lot and were chewing the fat rather loudly as I went by.

I arrived here well after dark, on account of the great valve project. I left the Flying-J right after I was done posting here yesterday, putting half a tank of fresh water in on my way out. I then headed straight for the Home Depot just a couple blocks west of here, and set up in their parking lot for the duration of the project. I was on track to be done and gone before dark, but I ended up on an unscheduled one-hour-plus Red Cross call, which put me behind.

Long-time readers have heard me grumble here about having to rebuild our hot water recirculating valves multiple times, an average of once per year per valve. The diaphragms are cheap, about $8 at Lowe's, but the valves are hard to access and the inevitable rebuild project is a royal pain, often involving muttered epithets from inside the cabinet, where I need to cram myself in order to take the valve apart. After the last round of rebuilds I decided that the next time they needed it, I would just replace them with something else, in the hopes that a different style of valve would not have the same problem.

For those joining us more recently, these valves allow us to get hot water to any of our fixtures (shower, kitchen sink, bathroom sink) without wasting a drop of water waiting for it to get hot. The water that would otherwise be running out unused into the sink or shower, additionally using up space in the gray tank, instead returns to the fresh water tank to be used later. For convenience, an electric push-button is located adjacent to each fixture to activate this water-conserving system, and the push-button opens an electrically operated valve or "solenoid." The system saves about half a gallon per use, and contributes to our 17-18 day self-sufficiency duration.

When we first installed the system we used Rainbird irrigation solenoids from the big-box store. They were relatively inexpensive and readily available, and they work on 24 volts which is our house battery voltage. They do a good job and have good flow, but the large diaphragm and relatively low pressure means they gather a build-up of calcium deposits any time we have hard water aboard, which it turns out is most of the time. Eventually the calcium deposits get large enough to interfere with the diaphragm's ability to seal, and the valve leaks slowly. In addition to running the pump unnecessarily, this can also run us out of hot water fairly quickly, and if we have an endless supply of power, it can heat the whole fresh water tank up to hot-water temperature if left unnoticed.

For the last month or so I have been keeping an eye open for a different type of solenoid with potable-water rating, 12- or 24-VDC operation, and enough flow to keep up with our 5 gpm pump. Oh, and I'm cheap, so $40-$50 per valve retail, which is what most water solenoids run, was over my budget. Eventually, however, I found a batch of new-old-stock appliance solenoids on eBay, and managed to score the whole lot of 20 solenoids for $22.50, shipping included. At $1.13 per solenoid, I can afford to keep a bunch of them around as spares in case these start to develop the same issue as the last ones.

These units are designed and sold for appliance water inlets, such as ice makers, drinking fountains, dishwashers, plumbed-in coffee makers, and the like. The manufacturer claims the diaphragm material is resistant to hard-water build up. They are rated at 14 gpm, work on 24 VDC, and of course are rated for potable water. Nearly perfect in every way, but with a configuration of inlet and outlet that presented a challenge.

Most appliances that connect to water systems use a garden hose style connector at the inlet, and the inlets on these valves are threaded for a female garden hose connection. The outlet is directed 90° from the inlet and is set up as a 3/8" tubing barb. My PEX water lines are terminated with 1/2" MIP threads, and so in to the store I went for a bunch of FIP to female garden hose fittings, as well as some 3/8" vinyl tubing, 90° barb adapters, and 1/2" threaded couplers.

I spent most of the afternoon crammed into each of three cabinets for what I hope to be the last time. Removing the old valves was the toughest part, as it is hard to swing a wrench in there.

The replacement hardware went right in, with the short length of tubing and a pair of hose clamps going on last. Should I ever need to replace one, it will be a simple matter of slipping the tubing off the barb, and unscrewing the garden hose fitting, a much easier process than rebuilding an irrigation valve in place, which involves removing six cover plate screws to access the replaceable diaphragm and spring.

After returning the inevitable unused parts to the store it was nearly 7pm. I rolled over here to the Wal-Mart, got settled in, and walked next door to Cowboy's BBQ for dinner. Apparently a Fort Pierce institution, it seems the shtick here is buxom young women in tight-fitting tops serving the food and tending bar. I ate at the bar, where house wine was 2-for-1 for happy hour, and they had a nice special on ribs and shrimp, which made putting up with such a homogeneous view all evening tolerable.

I was pretty beat when I walked back, but still made it into the store for some essentials, including a bottle of wine for this evening's dinner aboard Sandy Hook. I am expecting Martin to arrive from Orlando shortly, and we are due at the dock at 3:30. We've also lined up a tour of the new Nordhavn 63 in Stuart tomorrow, after which we need to stop by the Kubota dealer in Pompano Beach for a part before continuing on to the Miccosukee Resort for a few days of R&R with Stephanie and Martin before Trawler Fest.


  1. Great post, I truly wish I had some of your "fix-it" abilities. The only thing I would say is be mindful of the vinyl tubing as they tend to develop pin holes. But I would imagine you would have had that issue already if at all.

  2. Our Dometic fridge uses the exact same valve for the Ice Maker line. Our solenoid is 110V but otherwise mostly the same on hose connections. The thing I want to stress is that they are verrrrry easily frozen, and I have just changed one again. We find ourselves camping in freezing weather quite often, and it can cost us the plastic part of the valve under the diaphram. It appears that you have them installed inside the coach where heat is more often present on these cold nights. Rod

  3. Appreciate your comment about the RV ghetto. Rude and crude to say the least. Do admit we have to put one of the slides out so we can get into bed, but that's it. If we aren't in bed, we put no slides out at all. No jacks, etc. No mess, and no distraction to Walmart customers. We always do spend a little money in the store when we stop also.


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