hi can anyone help please?i have a problem with my hot tub.i have filled it,switched it on,power is fine.jets are working fine.however the circulation jet(think thats what its called)where the bubbles and heat come from in the bottom of tub,has no bubbles coming up!
have tried cleaning filters,and putting hose down the grey filter tube-bubbles come up from bottom of tub for a few seconds,then stop.dont know what else to try.any ideas please?thanks

If the tub is heating then the circulaton is fine. The bubbles are a result of an air/ozone mixture when water passes through a venturi valve. If you have none then it is most likely due to a lack of air from a clogged check valve.

In the motor compartment, you need to find the 3/4" line on the output side of the heater. It will have a black "T" valve in it with a 1/8" line coming from the top. Follow the 1/8" line up towards the top of the compartment. Somewhere in that line there is a small check valve. With the tub on, take the check valve out and see if you have bubbles. If so then just replace it.

ok thanks for that.gonna go take a look.

dan the spa man.thankyou sooo much.i did what you said,it had gunge in the tube-took out the check valve,it coughed and spluttered,turned it on and off,and ....it works!thankyou again.this is a brilliant helpful site.