Gash and pinhole leaksin copper tubing in pool heater

certain water heaters had a tube that dissolved, you take 1/2 in. copper flare one end of it, drill a1/8 in. hole in pipe 4 in. below flare ,remove cold water nipple on tank install new copper tube, cut tube to 3 inches off bottom of tank depth , reconnect cold water supply you should be good.

Or instead of assuming that the pressure switch is bad, it may be doing its job!!!

...try cleaning your filter first! Then... if you still have the problem, you can then check the pressure switch and the copper tube going to it.

The PVC plumbing is hooked into the front header, the front header is attached to the heat exchanger. The heat exchanger looks like copper finned tubes with a steel plate on each end. You need to disassemble heater working from top down to get to the exchanger. A skilled tech can replace an exchanger in under one hour service call.

You should valve the water off to stop the leak first. You can remove the complete line that is defective, usually a 1/4 inch tube either plastic or copper. Use two wrenches to loosen the compression nut fittings on each end, one wrench holds one part and the other wrench on the nut on the 1/4 inch line. Your local hardware store should have a kit or replacement parts readily available if you bring them what you removed, the water line and connecting device. It may be a good idea to replace the water filter while the water line is out of service. The water filter should be flushed out before using the water from it.

It is possibly coming from the heat exchanger. Most heaters have a copper tube style exchanger, capped at each end by plastic or metal headers. If the tubing has been subjected to any corrosive water condition such as low PH, low calcium hardness or very high cyanuric acid levels, the tubing may have deteriorated and is leaking. You may have dismantle the heater further and check for leaking.

I have the 250000BTU version but I believe they are the same in this regard.

It is far more likely to be simply that the low pressure detection copper line sprung a leak or is loose and perhaps dripping onto the limit switches. In and around the same area as the 2 hi-limit plugs is a small flexible copper tube (like for a refrigerator water line). Check that connection for a leak. The other end of that pipe is in the wire chase above the front panel. If you need directions on how to open either panels just ask.

sounds like you either have a pinhole in your heat exchanger or possibly a bad tube washer (seal). A pinhole can result from poor water chemistry or chemical exposure such as pH chronically low or a chemical feeder (chlorinator or salt cell) installed near the heater without a chemical resistant check valve. You will have to dismantle the heater far enough to access the heat exchanger and inspect it while the pump is running. If it's a pinhole in the exchanger, you will need a new exchanger. If its a seal, you will just need a new set of seals (washers) for the exchanger manifold.

That tube is the A/C drain port. Your problem is the heater core is leaking and draining from the A/Cdrain port. I hope this helps.
Thank You,
Roy

Never run plastic tubing through a wall! If copper is already there, then leave it, and solder the pinhole leak back up.

If the leak is outside of the wall, then cut off the tubing that includes the pinhole, and buy a brass ferrule coupling for 1/4 inch copper to copper. Make sure that it includes a brass barrel (it may come with 2, one for each side. If not, they are sold separately as well.). Install the coupling with ferrule into one side of the coupling.

Push the barrel into the plastic tubing, and install with ferrule just like you installed the copper tubing.

Sometimes you can get a plastic ferrule for the plastic line side of the coupling.