This is usually related to the dental compressor. The dental chairs need air to operate. Check the compressor and see if there is power and the pressure gauge is reading above 80psi on the pressure gauge.

At the base of the chair at floor level on the right side is a main power switch check to see if it is depressed. Cleaners and sometimes staff knock the button turning the chair off.

Check when the water filters were last replaced, this is the cause 99% of time. Call Dental Depot and we will organise replacement filters.

Check the Water Adjustment knobs on the right-hand side of the Bracket Table, there is an adjustment for each line make sure they are not turned off (wound fully anticlockwise). If the issue relates just to a high-speed handpiece line, swap the coupling and then the high speed handpiece with a known good one as the water pathways within your coupling or handpiece may be blocked;

Always firstly swap the handpiece with a known good handpiece that will confirm if it is the handpiece or a tubing issue.

No need for expensive chemicals, just a simple neutral detergent (Morning Fresh Dishwashing Liquid) is fine.