Spa attached to the pool suddenly lost water

Siphoning.

Ok, what next?

Thanks for answering he first question as to what is going on. Now what can I do to fix it?

It wasn't siphoning for the past week. What could have changed?

This is my first encounter with a house with a pool/spa. I don't mind troubleshooting if I can get access to documents/directions. Where would one find documentation about pools and resolving their issues?

It wasn't siphoning for the past week. What could have changed?

Click to expand...

Have no idea. Think back...What have you changed?

I'll venture a guess because I had a similar situation. The water is most likely flowing back into the pool through the spa inlet lines since the spa drained to a point level with these ports. There will likely be one or more check valves to prevent the water from flowing back into the pool because the spa is higher than the pool. There might be trash in a check valve that prevents it from sealing properly. I have also had one check valve fail internally and I had to replace the valve. Hopefully any check valves are accessible in the plumbing. If not, you might be able to add a new one somewhere on the line that connects the pool to the spa inlets.

David

If your spa has a bottom drain the valve for that suction line could've started leaking.

It seems probable that the inlet valve may have developed a leak as suggested since water is draining to the level of the top level jets. But if that is the case then it should drain to the level of lower level jets unless those have a separate valve.

So either there are two separate valves for each level of jets or each jet has its own valve and one of the top level ones has the problem.

I don't see any valve near the spa so it may be where the pool equipment is. Hard to figure out without a diagram of the system which doesn't exist for this 10 year old house/pool.

I think Post#5 contains the answer. I just didn't know how to explain all of that.

Years ago I had a maintenance account with an apartment complex and that included servicing the pool and hot tub. The mechanical room was a maze of plastic piping and weird valves and stuff. I never did understand any of that crap. I did all kinds of stupid things including draining the pool of about 10,000 gallons of water one night. If you have been "learning your system" recently you may have something turned the wrong way somewhere.

Yes, it could have been something that I did but the only learning I have been doing is by watching. I haven't changed anything. The only change I have observed is that the auto cleaning robot's flexible pipe has come off it connection on the pool wall. It's hard to imagine that was keeping the spa upper level jets from draining.

I learn a little bit every day.