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Electrical question

Discussion in 'Carver Yacht' started by Genewalerius4, Nov 8, 2016.

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  1. Genewalerius4

    Genewalerius4 New Member

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    my hot water heater on 38' Carver Aft Cabin cropped out. I'm thinking about a tankless water heater, 110v. I don't know breaker size of water heater on panel. No info in manual. Nothing on front or anything on inside of panel. Anyone 1- know what size this breaker is and 2- any suggestions on brand of tankless heater?
  2. Capt J

    Capt J Senior Member

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    The breaker will have it's rating on it somewhere, either on the lever or the breaker itself. You most likely cannot switch to tankless as they use a TON of amps when they do come on. Something your breaker, wiring, and shorepower/generator may not be large enough for.
  3. Pascal

    Pascal Senior Member

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    I had looked into tankless heaters after I installed a tub/jacuzzi in the master on my boat but quickly dropped the idea as the smallest I could find needed around 7kw. That's almost half my genset capacity.

    If you find something less power hungry I d love to know !
  4. Genewalerius4

    Genewalerius4 New Member

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    Home Depot sells one eemax? 12.5 amps 1440 watts draw. I'm sure it not raising temp by more than 30 degs or so at maybe 1 gal/min but all I do is shower for 2 mins and hot water for dishes. There is a rheem unit that will raise temp 40degs at .5 gym but it's the one that needs 30 amp breaker and #8 wire. I have the wire covered just can't find amp on breaker.
    I read on replacement water heater that went kaput that it drew 1500 watts at 15 amps.
    No luck on side/top/bottom inside or out! Nothing saying Brewer amps.
  5. Genewalerius4

    Genewalerius4 New Member

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    "Breaker"amps and .5gpm......
  6. Capt J

    Capt J Senior Member

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    Ok, but what size shorepower cord do you have??? If you only have a 120 volt/30 amp cord, the breaker will pop every single time the Rheem unit comes on.
  7. MAV

    MAV New Member

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    Typically the units are 15 amps. The breaker should have a label on the side with a rating but impossible to see if it's between two other breakers. Look at the wiring going to the tank, if the gauge is 14 awg (14/3), it'll confirm that the circuit is rated for 15 amps.
  8. Capt J

    Capt J Senior Member

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    That's not always true with wire size. If the run is longer, you'd need 12 gauge or even 10 gauge to carry the same 15 amp load. Also some builders use heavier wire than what's called for. Need to really look at the breaker. Many can say the amperage on the front lever or button also.
  9. ranger58sb

    ranger58sb Senior member

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    Before you rush right out to buy a new water heater...

    Sometimes failure can be at the thermostat, or at the element. Both are often replaceable, cheap parts (in the grand scheme of things). RV stores often carry replacement parts.

    -Chris
  10. MAV

    MAV New Member

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    Actually I beg to differ so I'll stick to my guns here. If we were talking about DC then I would agree on the size for length argument but we're talking about a hot water heater which is AC, so the length doesn't matter for our applications. 14/3 wire is rated for 15 amps AC, 12/3 for 20 amps AC, etc.

    As far as builders are concerned, it's extremely rare for them to oversize wiring for such a circuit as it adds additional production expense for something that would be completely unessassary.

    I do agree that the breaker should be checked as well and that some have a rating label on the front. The caution here is that you're assuming the current breaker is the original one from factory and that it was never replaced by a previous owner. If it was replaced and the owner didn't know what he was doing like installing a 20 amp breaker instead of a 15, then you'd currently have a fire hazard if the wiring is only 14 awg. If you then took this breaker spec and installed a 20 amp heater because you went by the breaker and NOT the wire size, then you'd have a big problem. You'd be running 20 amps through a wire rated for only 15 amps. Yes, check the breaker but it's the wiring NOT the breaker that dictates the maximum allowable load/appliance rating on that circuit's wiring.
  11. MAV

    MAV New Member

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    ++1