Water heater

[Yorkshirelad]

Hi Guys,
I switched the water heater on and after 20 minutes the plastic hose came off a compression fitting under the steps next to the pump. I took it all apart cleaned and reassembled and it held the water pressure. So a day later I switch the heater on again, the water starts to heat up but not really hot so I left on for another 30 minutes. Then sure enough the fitting separates again?
Do have rework all the plumbing or is there a pressure build up in the heater.?
Cheers Rob

 

[Lazy Daze]

It's unlikely you have pressure without hot water.

Are these the "slip on" fitting that you're talking about? The PEX tube goes in further than most think. Hold it next to the fitting to get an idea of how far it should go in and make a mark so you know it's inserted fully. Otherwise, the fitting is old and is not holding anymore. Under $10 to replace - HD, Lowes, FreshWaterSystems dot com.

You have a pressure relief valve on the heater, right?

If you're not getting hot water, the element or t-stat likely needs replaced - sounds like they're not "broken", but aren't doing their job as well as they should. Start with the element - pull it out and check it - could be caked up. HD/Lowes.

 

[Yorkshirelad]

Hi yes I get really hot water, I just reassembled the fittings. Tomorrow I will check the pressure relief valve. When I open the tap for the hot water there is a build up of air pressure before the water flows, only when I’ve had the heater on.

 

[ErikE]

Is this boat new to you? Sorry, I don't know all the folks here and the history.

Just asking as I am new to this class of boats and had some learning around tank water vs shore water and switching, purging air from the lines when doing so.

Not solving your line coming off issue, just the mention of air pressure comment.

The line coming off sounds like, as Lazy Daze said, possibly a fitting losing its holding ability.

 

[Lazy Daze]

I'm confused... in your first post you said you didn't get much hot water... but in your second post you said you get really hot water?

The "pressure"... or more likely, air escaping, could be because you haven't let the HWH tank completely fill - this will happen if you don't totally bleed the system - just like it would with your home's HWH.

 

[bobeast]

Your press-in PEX fittings should not be blowing out. They should be able to handle the pressure added by the heat of the water, up to and beyond the blowout valve on your water heater. That pressure valve should be the "weak link" in your system.

You might consider replacing that pressure valve on your water heater.

You may need to replace one or more of those fittings and/or lengths of PEX. If you do so, be aware that PEX comes as either imperial (½") or metric (15 mm). The two are close enough in size to fool you into thinking they are interchangeable. They are not. Most PEX tubing and fittings at local hardware stores is ½". At least on my 2002, Sea Ray used 15mm. So make sure you order the correct bits according to what's installed on your boat.

 

[markrsimon]

Depending on the fitting - you may be missing the steel retaining washer. If you have a similar fitting elsewhere, take that apart carefully - studying/taking pictures, so you have a know assembly sequence. Compare that to your problem fitting.

On mine, that steel one-way ring is what prevents the pipe from working its way out - when under pressure.

 

[Island Time Buffalo]

I had a perfectly new compression fitting blow off the water heater, nearly sunk the boat because I got a little lax with turning off the city water when leaving the boat - burned out 2 bilge pumps and flooded the mid-berth floor. Needless to say, I am now a fanatic about turning off the water.

... but back to the point. Even new fittings can fail and it may have nothing to do with pressure or temperature.

In my case the fitting was "L" shaped and I was able to get zip ties to hold it in place to finish my Lake Erie vacation. The seal was perfectly good, just couldn't hold on.

.

 

[Yorkshirelad]

Thank you for all your inputs, yes I took the other fittings apart to check. I didn’t find a steel washer in the assembly, so my be I will head to Home Depot this week and look at replacing the fittings.
Cheers Rob

 

[Henry Boyd]

Thank you for all your inputs, yes I took the other fittings apart to check. I didn’t find a steel washer in the assembly, so my be I will head to Home Depot this week and look at replacing the fittings.
Cheers Rob

Rob,
Do some measuring first. Sea Ray built boats with two different size plumbing. One is 15mm od, the other (like US plumbing) is ½” od. The 15mm is usually only available from RV and boating supply houses, whereas any home or plumbing supply will have ½”. And a FYI, the two are not compatible. Our 02 280 had 15mm, our current boat (not a SR) uses ½”. Regardless of size, if the tubing is cut cleanly and square the parts fit just fine. If you have to shave this, or ream that, odds are you are working with mismatched pieces.

 

[Yorkshirelad]

Hi Henry,
Yes the tube is 1/2” I have attached a picture of the birds nest I inherited!

 

[Pirate Lady]

Hi Henry,
Yes the tube is 1/2” I have attached a picture of the birds nest I inherited!

Dear god, was that designed by a congressional committee?

 

[Yorkshirelad]

Exactly lol

 

[Lazy Daze]

As long as you're going to be in the nest and correcting things, remove that electrical tape and check out the connections. Remake them with butt connectors if needed (adhesive lined are nice!). I question whether or not there's actually a connector there or if the wires are just twisted together..... and cut those darn zip tie tails off!

 

[Yorkshirelad]

Will do!