Plumbing

[HawkX66]

My 97 290DA has John Guest 15mm push to connect fittings. Are these factory or did someone replace the plumbing lines? I'm cleaning up from the water holding tank through the pump and water heater and wanted to change out a few fittings. I'm having a tough time finding them and wondered if I should just go with 1/2" Pex or Shark bite etc.

Thanks.

 

[Henry Boyd]

15mm is what was used on many of the boats in the line up. Future fittings on later models were sourced from Sea Teq. Freshwatersystems.com has everything you need. I’d recommend keeping it all 15mm just to keep all of the parts straight.

 

[HawkX66]

15mm is what was used on many of the boats in the line up. Future fittings on later models were sourced from Sea Teq. Freshwatersystems.com has everything you need. I’d recommend keeping it all 15mm just to keep all of the parts straight.

Thanks for the info!
The only thing that keeps me thinking about changing to 1/2" is the ease of going to Lowes or the Depot and picking up a replacement. There's only a few feet of tubing to replace so it would be easy to swap everything over.

 

[Stee6043]

+1 on freshwatersystems.com. They are great. And yeah, the fitting size is a real PITA. But I never had the heart to swap to local sizing...

 

[Little Ducky]

Your understanding is reasonable but once you start to change over to a difference size that's just more spares you would have to keep onboard.

 

[HawkX66]

I'm probably going to go ahead and do it while I have the water tank and the water heater out. The only thing that will be a bit of a pain is running 1/2" line to the head and the sink, but I don't think that will be a big deal. If I swap everything over there aren't multiple sizes that I'll need to carry. They'll all be the same size and easily replaced.

 

[Lazy Daze]

You might be creating a lot more work for yourself than you need. PEX lines don't really go bad - or, at least, it's extremely rare. Just flush them with a clorox/bleach solution and let it set for a bit. Then flush with water a few times and you're good to go.

 

[HawkX66]

You might be creating a lot more work for yourself than you need. PEX lines don't really go bad - or, at least, it's extremely rare. Just flush them with a clorox/bleach solution and let it set for a bit. Then flush with water a few times and you're good to go.

Right. I get that they don't go bad, but the prev owner didn't finish installing the new hot water heater and left things open. They got a little grungy. Not really a big deal obviously, but I just feel like replacing them and making the plumbing all new with SAE fittings vs metric. It really isn't a hard or expensive job if you're doing it yourself. With how hard it was to source the 15 mm fittings, it kind of reinforces it for me.

 

[uplander]

The crimp on 1/2” pex fittings will work. The ID for the 15mm PEX is slightly smaller than the 1/2” PEX. Some of them take a bit more pressure to push in; a small heat gun makes it a snap to insert them. Attached is a photo of my hot water tank bypass setup using 1/2” fittings and 1/2” and 15mm PEX.

I’m not sure I’d trust 1/2” push on Sharbites since the 15mm OD is a bit smaller. (I really don’t like the push on fittings in any application.

 

[HawkX66]

The crimp on 1/2” pex fittings will work. The ID for the 15mm PEX is slightly smaller than the 1/2” PEX. Some of them take a bit more pressure to push in; a small heat gun makes it a snap to insert them. Attached is a photo of my hot water tank bypass setup using 1/2” fittings and 1/2” and 15mm PEX.

I’m not sure I’d trust 1/2” push on Sharbites since the 15mm OD is a bit smaller. (I really don’t like the push on fittings in any application.

Thanks for the info. If I did make the change there wouldn't be any 15mm left. I'm still not sure if I'm going to do it. If I'm able to clean the fittings well enough for my liking and I don't need to replace any, I might just stick with what I have.

 

[Lazy Daze]

I'd go with the KISS method. Now that you know an easy place (fresh water systems... which also gets my vote) to get the 15mm pieces, I wouldn't worry about changing everything. In reality, if you had one or two spares, that's all you'd need for the next decade or two.

 

[ojet]

Thanks for the info. If I did make the change there wouldn't be any 15mm left. I'm still not sure if I'm going to do it. If I'm able to clean the fittings well enough for my liking and I don't need to replace any, I might just stick with what I have.

Freshwatersystems.com sells a push on connectors to join the 15mm to 1/2 pex. This will make it easy for repairs or making a water heater bypass.

 

[bbwhitejr]

West Marine sells some 15mm fittings, but they are out of sight expensive.....

Bennett

 

[HawkX66]

West Marine sells some 15mm fittings, but they are out of sight expensive.....

Bennett

Thanks. I just ordered some online. Still pricey, but not too bad.