Surge damper in front of propane water heater?

_OS__OS_ Solar Expert Posts: 207 ✭✭✭
First, please excuse me if this post is inappropriate for this forum.

I am installing a water system in my cabin and have a question around the installation of a propane water heater. In the installation diagram from my dealer they have specified a Whale surge damper in front of the cold water inlet of the water heater. My question is, is this really necessary? I know what this device is supposed to do but I am trying to keep the number of bends, pipes and so on down because the propane heater will be mounted on the bathroom wall.

My brother has a propane heater from another vendor in his cabin and they have not specified a surge damper.

Thanks,
OS
«13

Comments

  • sawmillsawmill Solar Expert Posts: 93 ✭✭✭
    Re: Surge damper in front of propane water heater?

    The use of a surge damper would only be useful if your water supply is not smoothe.

    If this is an on demand heater then the water flow would need to be steady to avoid turning the heater on & off when the water flow changes.
  • Dave AngeliniDave Angelini Solar Expert Posts: 5,029 ✭✭✭✭✭
    Re: Surge damper in front of propane water heater?

    There can be problems with shortened pump life if the the pump is physically close to the water heater. A one way valve or small expansion tank will keep back pressure from damaging pump seals from pressure building on the pump output.

    I would use an expansion tank as it will also reduce pump cycles. It does not need to be a big tank! Some of the reverse osmosis system sites or water internet companies have tanks in the $30 range.

    So to some it up, do something or the pump could fail in as little as 6 months time if it is within 5 feet of your water heater.
    "we go where power lines don't" Sierra Mountains near Mariposa/Yosemite CA
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  • dwhdwh Solar Expert Posts: 1,341 ✭✭✭
    Re: Surge damper in front of propane water heater?

    That surge damper looks to me like a "water hammer arrestor".

    Basically, a shock absorber.

    http://www.psdmagazine.com/ASPE_memberpdf/Mar_Apr_03/10-11.pdf

    If the water heater manufacturer specifies a shock absorber (or surge dampener or water hammer arrestor - call it what you will), then I'd definitely use one.

    Though you might achieve the same result by using an accumulator.
  • icarusicarus Solar Expert Posts: 5,400 ✭✭✭✭
    Re: Surge damper in front of propane water heater?

    I think the real reason to use one,, is if you have fluctuating pressure,, the output of the heater will vary,, causing the temp to rise and fall as the pressure changes on the water diaphragm. I have found that if you run a system on ~20psi or better I haven't had any trouble. Below that,, they get very sensitive.

    What brand heater,, model number etc might help,,, a link?

    Tony
  • _OS__OS_ Solar Expert Posts: 207 ✭✭✭
    Re: Surge damper in front of propane water heater?

    Thanks for all the replies! I do not have the exact model number of the heater but the brand is Sylber and the size is 11 liters/minute. I have searched Google but did not find anything other than a picture:
    1485_107.jpg

    I have also scanned the installation diagram from my dealer. To the left in the scan below is the water tank (I have a fixed pipe, not a "straw" like the picture, between the pump and the tank). Circled in red is the mentioned surge damper. I also have a Shurflo "Classsic" 230V AC water pump instead of the one in the diagram below. Picture of the pump:
    Standard-Pump.jpg


    Question; would it be better to put the surge damper on the output of the pump instead such that the cold water would be damped as well?

    water.JPG
  • mike95490mike95490 Solar Expert Posts: 8,614 ✭✭✭✭✭
    Re: Surge damper in front of propane water heater?

    The damper IS connected to the cold water pipe, roughly about 80% for the other cold fixtures. The heater is the "delicate" part, and needs the 100% protection.

    What are the 2 gadgets hanging off the cold water line ( # 551270 ) ? I also see a flex line on the hot output, likely to accommodate the thermal expansion of the pipes when heated, rather than flex the internal parts.

    I also like to install a "damper" or anti hammer in the washing machine lines (H & C), as the solenoids switch off, they can impart an awful BANG. Also on the toilet feed, as the float valve shuts off, Bang.
    Powerfab top of pole PV mount | Listeroid 6/1 w/st5 gen head | XW6048 inverter/chgr | Iota 48V/15A charger | Morningstar 60A MPPT | 48V, 800A NiFe Battery (in series)| 15, Evergreen 205w "12V" PV array on pole | Midnight ePanel | Grundfos 10 SO5-9 with 3 wire Franklin Electric motor (1/2hp 240V 1ph ) on a timer for 3 hr noontime run - Runs off PV ||
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  • Dave AngeliniDave Angelini Solar Expert Posts: 5,029 ✭✭✭✭✭
    Re: Surge damper in front of propane water heater?

    My comments on protecting the pump were based on you having a tank type heater. In a tank system when the house pump turns off and the hot water heater comes on (solar or gas) there can be huge pressure spikes on the house pumps output that can damage it if the pump is close to the hot water heater. This happens often with solar hot water in new installations.

    With on demand you should use what is reccomended for your system.
    "we go where power lines don't" Sierra Mountains near Mariposa/Yosemite CA
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  • _OS__OS_ Solar Expert Posts: 207 ✭✭✭
    Re: Surge damper in front of propane water heater?

    Hi Mike,

    The two 551270 are drain valves that must be mounted on the lowest point and are used to let all water out before the winter (I am sorry I do not know what you call this in English).

    I do not know why the flex line is there but it did come with the heater.

    OS
  • icarusicarus Solar Expert Posts: 5,400 ✭✭✭✭
    Re: Surge damper in front of propane water heater?

    Ole,

    The flex lines come with the heater to allow easy installation I believe.

    As for a surge damper. I really think that it is there to prevent surges in pressure resulting in the flame being altered and the temperature fluctuating.

    I had a case (in a shingle handled faucet set up) once that when you turned the hot down because the shower was too hot,, it would reduce the flow RATE through the water heater, and the temperature would go UP instead of down! I solved it by changing the faucets out,, but the modern modulating heaters do a pretty good job.

    I have dealt with Sibire with LP fridges,,, never with water heaters. Contact them and see what they say,, or install the surge damper, or take a gamble and not worry about it.

    Good luck,

    Tony
  • _OS__OS_ Solar Expert Posts: 207 ✭✭✭
    Re: Surge damper in front of propane water heater?

    Hi Tony,

    Yes I will install the surge damper but today I traded in the 11 liters/minute unit with a 6 liters/minute for two reasons; the 11 liters unit is very big and requires an exhaust pipe (6 inch diameter or bigger) through the wall or ceiling. The 6 liters is much smaller and need only good ventilation.

    Her is a picture taken from the door right after painting the pine panels white:
    IMG_0356.JPG

    And here is the (80 liters) water tank in the corner. I will try out the system with everything in the bathroom at first. Then maybe I will build a technical room or something later. The problem is that it is a small cabin and not much extra space. This room used to be a bedroom.
    IMG_0355.JPG

    I will post more pictures when I have started installing.

    Ole
  • CariboocootCariboocoot Banned Posts: 17,615 ✭✭
    Re: Surge damper in front of propane water heater?

    The schematic shows the system set up with a 12 volt, pressure-switched pump as might be found in an RV. This means the pump will turn on/off as its switch senses pressure drop/fall. The pressure at the heater will be different; possibly enough to cause unwanted cycling of the burner. The "Trykkutjevning" is a small anti-hammering device to try and keep flow to the heater consistent. (These are frequently used on hot water heating systems, and are frequently just very tall pieces of capped-off pipe.)
    Under the circumstances, I'd recommend using a 10-20 gallon pressure tank with the pump control switch at the tank. This should mediate water pressure safely within operating range and reduce pump cycling.
  • icarusicarus Solar Expert Posts: 5,400 ✭✭✭✭
    Re: Surge damper in front of propane water heater?

    Cariboo,,, BINGO!

    A big enough P tank and you don't need any surge protection.

    If you are only going to use the pump and no P-tank then you are right about needing something to keep the pump from cycling and the pressure from bouncing.


    T
  • _OS__OS_ Solar Expert Posts: 207 ✭✭✭
    Re: Surge damper in front of propane water heater?

    I almost finished installing this weekend. I did not test it out because I could not connect the gas; the connector that came with the unit was of a different size than I use (I use 3/8" pipes).

    IMG_1166.JPG

    IMG_1172.JPG

    IMG_1165.JPG
  • CariboocootCariboocoot Banned Posts: 17,615 ✭✭
    Re: Surge damper in front of propane water heater?

    Very neat installation!

    A couple of questions/notes:

    What sort of pipe is that? Looks like PVC or PEX (we don't have those connectors here). Does not the heater's manual call for metal piping within 5' of it? Mine did.

    Also, be sure your gas lines are the correct size for the heater. Starving it of fuel or varying the pressure will adversely affect its operation.

    You might want to add some more vibration dampening to the pump; they can be noisy.
  • _OS__OS_ Solar Expert Posts: 207 ✭✭✭
    Re: Surge damper in front of propane water heater?

    The pipes are 15mm Whale Quick Connect that are very popular in RV, boats and cabins in my country (www.whalepumps.com). This system is very easy to install but the elbows, tees and so on are more bulky than many other types.

    On the hot water outlet there is a 6 inch flexible metal pipe (see installation diagram above). Other than that there are no requirements.

    I plan to build a "box" around the installation and put some sound damping material on the inside.
  • mike95490mike95490 Solar Expert Posts: 8,614 ✭✭✭✭✭
    Re: Surge damper in front of propane water heater?
    _OS_ wrote: »
    I plan to build a "box" around the installation and put some sound damping material on the inside.

    You will conduct sound right thru the mounting base of the pump, and turn the whole floor into a soundboard. put a layer or 3 of rubber padding in there, it will help a lot.

    PUMP
    ~~~~~~~~~~~ rubber
    Plwoood
    ~~~~~~~~~~~ rubber
    Floor
    Powerfab top of pole PV mount | Listeroid 6/1 w/st5 gen head | XW6048 inverter/chgr | Iota 48V/15A charger | Morningstar 60A MPPT | 48V, 800A NiFe Battery (in series)| 15, Evergreen 205w "12V" PV array on pole | Midnight ePanel | Grundfos 10 SO5-9 with 3 wire Franklin Electric motor (1/2hp 240V 1ph ) on a timer for 3 hr noontime run - Runs off PV ||
    || Midnight Classic 200 | 10, Evergreen 200w in a 160VOC array ||
    || VEC1093 12V Charger | Maha C401 aa/aaa Charger | SureSine | Sunsaver MPPT 15A

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  • icarusicarus Solar Expert Posts: 5,400 ✭✭✭✭
    Re: Surge damper in front of propane water heater?

    Ditto What Mike suggests re: noise. If noise is a real problem,, you can isolate the pump vibration with a loop of pipe on each end such that the loop absorbs the rat-a-tat of the pump.

    Cariboo,,

    Marc,

    Those fittings are "Shark Bite" Fittings They are really cool as they fit PEX, PVC, CPVC, Copper all in one REMOVABLE fitting. You can join copper on one end, PEX on the other end for example. They are great for repairing freeze damage since you don't need to dry pipe to repair. They are approved for in the wall service,,, and you can take them apart and reuse them.

    They are too spendy to do your whole house with,, but for small stuff and repair work they are great.

    Tony
  • CariboocootCariboocoot Banned Posts: 17,615 ✭✭
    Re: Surge damper in front of propane water heater?

    Thanks, Tony!

    I look forward to driving the local plumbing supply place nuts by asking for them. :p

    We do have a similar connector here, only the outside is like a big nut. I used them throughout the cabin; they will also go on copper and can be re-used if you don't damage them.

    I was going to mention that the Op might want a bit of flexible line on the output side of the pump as well to help absorb vibration, but I forgot because I'm old. :p
  • icarusicarus Solar Expert Posts: 5,400 ✭✭✭✭
    Re: Surge damper in front of propane water heater?

    Home depot stocks them in the states,,, and in Thunder Bay,

    T
  • _OS__OS_ Solar Expert Posts: 207 ✭✭✭
    Re: Surge damper in front of propane water heater?

    Thanks for the replies everybody!

    My problem now is that the gas inlet of the heater has 3/4 inch male threads and the adaptor (hose?) that came with the unit has a pipe that is around 14mm thick and nobody use that thickness over here. We use 3/8 inch pipes for propane. This picture shows the adaptor that came with the unit:

    IMG_1382.JPG

    I believe the threads are 3/4 inch and they fit the heater but the pipe is too thick.

    I went back to the dealer today and they had two more heaters in stock and both had the incorrect fitting. They then made this "pyramid" that they told me to use:

    IMG_1383.JPG

    The threads in the thick end are the same, 3/4" and the thin end is of the quick connect 3/8 inch type for propane tubes so everything is of the correct size. But I am afraid that the thickest unit (the one that reduces from 3/4 inch threads to 1/2 inch threads) is one that is made for water pipes and will not get tight enough for propane. Any experts here?
  • Solar GuppySolar Guppy Solar Expert Posts: 1,962 ✭✭✭
    Re: Surge damper in front of propane water heater?

    Propane should have a regulator and the pressure at the heater should be no more than water pressure, probably a lot less. When you do the install, use soapy water and check for bubbles, also I would use pipe dope on all the threads to help seal.
  • icarusicarus Solar Expert Posts: 5,400 ✭✭✭✭
    Re: Surge damper in front of propane water heater?

    General FYI

    Regulated propane gas pressure should be ~11-13" of Water measured with gas pressure manometer. (You can make a simple manometer with a clear tube of pipe,, should be able to find directions on line) 11-13" = ~1/2 psi. That is after the regulator!

    Natural gas should measure ~ 8" if memory serves,,,I don't deal with natural gas.

    (North American specs)

    Now in Ole's case it might be something different, check the rating plate of the unit and it will specify proper gas pressure.

    Now for the specific piping question, I can't really see what the fittings are. Gas fittings in N. America are either Iron Pipe thread or Flare fittings. Making a transition from one to another can be quite tricky.

    After you have assembled the entire gas net work,, turn off the gas valve at the appliance and pressurize the system with air if you can. The easiest way to do this is with a fitting plumbed into a tire valve,,,then you can use a hand pump or a small compressor to pressurize the entire system. The proper way to do it is to pump it up to ~15 psi,, wait 15 minutes and see if the pressure drops. If you don't have a gauge you can soap bubble each fitting at this higher pressure to ensure that it will hold the lower system pressure. Please note that you should never pressurize an appliance this way or you potentially damage all kinds of things like diaphragms etc. So use a isolation valve before any regulator or appliance.

    If you can't test any other way,, a simple soap bubble test is a second choice. A simple spray bottle with a rich mixture of liquid dish soap sprayed on EVERY fitting will reveal any leaks. The caveat with this method it that it only tests to regulated pressure,,,,~1/2 psi,, so in the event of a regulator failure,,, your system could leak where it wouldn't under normal pressure.

    I believe that "normal" Propane tank pressure is ~150 psi, so any piping before a regulator should be tested to a safe design psi.

    Remember,,, working with gas can be very dangerous so treat it and it's fittings with respect!

    Tony
  • dwhdwh Solar Expert Posts: 1,341 ✭✭✭
    Re: Surge damper in front of propane water heater?

    Saw a great sound isolation mounting for an RV water pump one time...

    It was made of 4 strips of old tire, and the strips were bent into a C shape.

    Like...
    PUMP
    [space]
    FLOOR

    Worked great.
  • CariboocootCariboocoot Banned Posts: 17,615 ✭✭
    Re: Surge damper in front of propane water heater?

    _OS_: It's hard to tell what those fittings are without seeing them in person. Is the connection to the heater pipe thread, or is it a 3/4 dia. flare nut fitting? Stacking lost of fittings close together is not recommended for any application. Gas fittings must being either pipe thread or flare. For pipe thread there is a special Teflon tape specifically for gas fittings. It is thick, yellow, and in my opinion is better than liquid-type dope. DO NOT use ordinary thin, white Telon! Flare fittings of course do not get taped or doped.

    Tony's method of leak testing is best, and do be sure you've got the right regulator in place as per manufacturer's specs. You should also have a moisture trap at the regulator; it's just a short piece of capped-off pipe that hangs down. Any moisture in the gas will fall out of the stream and collect there. Gas is tricky and dangerous: Be Careful!

    Tony: our nearest HD is 500 kms away, and they don't stock the Whale fittings. I don' really need them, but they sound interesting!
  • icarusicarus Solar Expert Posts: 5,400 ✭✭✭✭
    Re: Surge damper in front of propane water heater?

    Marc,

    Home Hardware can order them,,I think CT carries them as well.

    As for the teflon tape debate. When I came up,, tape was banned because the seal could be compromised if you had to loosen a fitting a 1/2 turn to get it to line up properly. I have always used gas rated thread sealer (brush on) and have had great luck.

    As you suggest,, flare fittings should never be taped or doped. Gas should only be IP threads or flare,,, although I have seen in some british made units COMPRESSION fittings. There is no reason they won't seal,, but there is no mechanical joint, so you could have a case where something could pull it apart.

    Tony
  • _OS__OS_ Solar Expert Posts: 207 ✭✭✭
    Re: Surge damper in front of propane water heater?

    Hi Marc,

    The thin end of the fitting above is a flare fitting. The other (thick) end that connects to the heater has regular 3/4" threads. Or at least I believe so because I can fasten it to at male 3/4" unit for water that I have.

    The shop told me to use something called Loctite on the threads but they did not have it in. I will also try to find the thick, yellow Teflon tape you mentioned.

    OS

    PS: Some of you probably wonder why I have the water tank inside the cabin instead of somewhere outside (under the cabin or something). The reason is that the regulations in my country say that I can let the wastewater go right into the ground if I carry the water into the cabin. If I run the water from the outside in a pipe through the wall/floor I have to install a very expensive wastewater cleaning system.
  • CariboocootCariboocoot Banned Posts: 17,615 ✭✭
    Re: Surge damper in front of propane water heater?

    Loctite is for 'locking' threads of mechanical applications. It is used largely on engines. It is NOT suitable for gas fittings! It is NOT approved for gas fittings! They should NOT be recommending it for such. (Caveat: unless Loctite makes a gas pipe dope I don't know about.)

    I've never had a leak with the Teflon tape on any pipe connection. Can't say the same about dope, but that's probably just coincidence.

    If your heater fitting is 3/4 pipe, there shouldn't be any problem getting an adapter to reduce it to 3/8 pipe in one go. Although I'm leery about that sudden change in pipe size; be sure and consult the heater's install manual regarding placement of regulator, water trap, and pipe sizing. Most often they want a regulator directly at the heater; whatever pipe feeds that then becomes a 'non-issue'.

    As for regulations, this forum frequently points out how they very from one place to another, even within the same country, and change over time. I've just been told here that 'S' traps are no longer approved for drains, because of venting issues. Funny, we've used them for decades even without vents (they run a bit slow that way). But people will do things wrong and put them in where the stack is too far away so a new reg has to be written.

    This 50+ year-old cabin of mine had gas piping of every sort, including compression fittings and 5/8" tubing. It leaked 20 lbs. per week. I tore it all out one Sunday when I was bored and did it right.:D
  • _OS__OS_ Solar Expert Posts: 207 ✭✭✭
    Re: Surge damper in front of propane water heater?

    This weekend I managed to connect the gas to the water heater as well as the stove and fridge. I finally got the yellow sealing tape and have not used Loctite.

    Here is a picture of the copper pipe with valve to the propane heater (sorry for the poor quality, I shot it with a cheap camera):

    IMG_1397.JPG

    I also bought a leak detector (at about $120 it was expensive but well worth it) that I inserted right after the outlet on the propane tank:

    IMG_1404.JPG

    The propane is stored in a safe locker outside my cabin:

    IMG_1401.JPG

    I also runned the copper pipe diagonally under the cabin to where I have the stove and fridge. I drilled a hole through the floor under the fridge (which rests on an 8 inch home made socket):

    IMG_1400.JPG

    And guess what? I took my first ever shower in my cabin today! The hot water pressure was low but enough to take a quick shower.

    The temperature outside today was among the hottest I have measured; 28 C
  • CariboocootCariboocoot Banned Posts: 17,615 ✭✭
    Re: Surge damper in front of propane water heater?

    You've done a very neat and professional install, except for one thing: get rid of that rubber hose & clamps at the tank! That's definitely not approved gas-fitting and it is dangerous. There are flexible lines approved for gas, with fixed fittings.

    Note to moderators: I think we need some new emoticons for "worried", "scared", and possibly "terrified".:p
  • _OS__OS_ Solar Expert Posts: 207 ✭✭✭
    Re: Surge damper in front of propane water heater?

    Hi Marc,

    Thanks! The rubber hose and clamps are allowed in Norway where I live but I might upgrade to an automatic change over valve for two tanks later (see picture below). There is a big drawback with the automatic changer; it requires an industrial type fitting on the gas tanks and they are more expensive to refill.

    omskifter.jpg
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