Herga

Herga air buttons and pneumatic controls for pools and spas

Pneumatic control is the standard way to switch pumps, blowers and lighting on a wet deck without carrying mains voltage to the point where a wet hand touches it. Pressing a soft button displaces a small volume of air, that pulse travels down a length of flexible tube, and an air switch mounted in the dry side of the equipment pack does the actual electrical work. Herga is a long-established name in this field, and its air buttons are found on spa shells, swim spas, jetted baths and pool decks where a sealed, low-voltage-free control is needed. Here we list the Herga parts carried for repairs and replacements.

What an air button does and why it fails

The button itself is a simple device: a flexible cap over a small chamber, with a barbed spigot underneath for the air tube. Because it is simple, it usually fails in one of a small number of ways, and all of them are easy to recognise once you know what to look for.

• Perished or split cap — years of chlorinated or brominated water, sun and suncream harden the PVC until it cracks. The button may still feel firm but no longer displaces enough air to trip the switch.
• Loss of air seal — a hairline split, a tired O-ring or a loose mounting nut lets the pulse escape instead of travelling down the tube. The symptom is a button that works intermittently or only when pressed hard and fast.
• Water ingress — water that gets past the button sits in the tube and dampens the pulse. Blowing the tube clear often restores function temporarily, which is a strong hint that the button is the culprit.
• Cosmetic wear — chalky, discoloured or stained caps on an otherwise sound spa. Replacing the button is far cheaper than replacing the control system.

Before condemning the button, test the rest of the chain. Pull the tube off the button, press the end against your lips and give a short sharp puff: if the pump or blower responds, the air switch and tube are sound and the button is at fault. If nothing happens, the fault lies in the tube, the switch or the electrics.

Identifying and fitting the right button

Air buttons are not universal. The parts that matter are the mounting hole diameter in the shell or deck, the thickness of the material the button clamps through, the style of the retaining nut and the barb size for the tube. Measure before ordering rather than judging by the visible cap, because buttons of very different sizes can look alike once installed.

• Hole size — remove the retaining nut from below and measure the bare hole in the acrylic or deck, not the outside of the trim ring.
• Material thickness — acrylic shells, reinforced shells and timber or composite decking all differ, and the threaded body needs enough reach to clamp up tight.
• Diâmetro do tubo — pneumatic tubing for spas is commonly a small-bore flexible line pushed over a barb. Check that the existing tube seats firmly on the new spigot.
• Access from below — most buttons are fitted from the top and secured with a nut underneath, so plan for access to the back of the panel before you start.

When fitting, keep the tube run as short and as free of low points as possible. Loops that trap water are the most common reason a newly replaced button still behaves erratically. Hand-tighten the retaining nut with the sealing washer seated squarely; over-tightening distorts the body and can itself cause a leak.

Soft PVC versus rigid buttons

A soft PVC button has a flexible touch surface that deforms under the finger, which gives a light action and a forgiving feel underfoot or under a wet hand. Rigid-top buttons use a separate internal bellows instead. Soft caps are pleasant to use and easy to press, but the flexible material is the part exposed to water chemistry and UV, so it is the part that eventually needs renewing. Keeping a spare on hand is sensible on any installation where a single button controls a pump or blower that bathers rely on.

Herga at PoolParthub.com

Here you will find the Herga soft PVC air button 6433, a replacement pneumatic button for spa and pool installations where the original has perished, split or lost its seal. It is stocked as a direct repair part for systems already built around pneumatic switching, so an ageing control point can be renewed without touching the air switch, the tubing or the wiring behind it.

If you are unsure whether this button matches your shell, measure the mounting hole and the thickness of the panel and compare them with your existing part before ordering. Alongside it, the wider catalogue covers air switches, pneumatic tubing and the pumps and blowers these controls operate, so a complete control chain can be repaired in one go.