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Leaks in hot tubs can seem hard to find, but it's not
difficult if you know where to start. Look
for water under your pump first, as a common cause is bad pump
seals. Also check around your heater, pressure switch and all interior
plumbing, unions, and connections. |
If you decide not to tear into the
equipment, use of a quality
 leak
sealer can save you some time and repair money. Although not always a permanent fix, they can be
effective on many leaks, with the exception being bad pump seals, which will need to be replaced.
Components associated
with spa leaking:
- Pump Wet End Seal
- Heater Assembly Manifold
- Slice/Knife and Gate Valves
- Plumbing Tubing
- Jet Bodies
- Acrylic Spa Shell
- Wooden Hot Tubs
Step-by-Step Repair Diagnostics
A) Disconnect all power to
the spa. Inspect the equipment
compartment. If leak is under the pump, this indicates a possible pump seal failure.
If leak is detected, replace pump or install new seal, as appropriate.
B) Check all union fittings
at hot tub pump and heater. Unions can even vibrate loose on a brand new spa during shipment, and should be hand tightened
if necessary. If hand tightening is difficult, loosen pump mounting bolts, move components
into alignment, then tighten unions and retighten pump mounting bolts.
Never use a wrench to tighten spa unions.
C) Next, inspect heater, pressure switch and surrounding
components. Replace any defective parts as indicated by leak.
See  Heater
Testing
D) Inspect all of the valves. Repair or replace if leak is
indicated. Knife style valves are sometimes bolted together and contain a gasket between the halves
which can fail, particularly upon freezing or with prolonged poor water quality conditions.
Note: Valves on either side
of the pump, when present, are installed at the factory as a
convenience to service people (so that they do not have to drain the
spa water to replace a pump). In reality, these valves more
often do more harm than good, since they are a common source of leaks.
Some hot tub owners choose to remove these valves if they have been a
leak problem source.
E) Inspect all pipes, jets and connections for
leakage. Repair or replace if indicated.
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There is only one product that we have ever
found that can reliably and permanently fix leaky PVC components:
Plast-Aid.
This product forms a molecular bond with the plastic which is stronger
than the PVC pipe itself. It is far superior to epoxy compounds. |
Leak Detection
One method for locating leaks is to use dye (dark food color) in the water. This
method works best if the leak is substantial. Observe location of dye leakage, using flashlight
if needed, and proceed with repair.
Another method is to is to let the water drop (with spa
not running) and then observe the water level of the spa when the level ceases to drop. If
the water stops dropping at a jet for example, that jet is the likely leak source.
For faster leaks it may help to determine the type of leak: vessel leak (spa shell), suction-side
leak (before pump) or pressure leak (after pump). Fill spa and mark the water level with grease
pen or crayon, and allow the spa to run for 24 hours. Now mark the new water level to determine
how much the water level has dropped. Refill to original mark, and keep system off for 24
hours. Again, note how far the water dropped. If the water dropped the same amount on both
tests, this usually indicates a vessel leak (blisters and most surface cracks are usually
only cosmetic, and not normally a cause for leaks). If the water dropped more with system
running, this indicates a pressure leak. If the water dropped less with system running, this
indicates a likely suction leak.
Repairing Shell Cracks
Most so-called shell leaks are
actually leaks associated with jets or other fittings, not the shell
itself. Today's hot tub shells are cast acrylic which has been
vacuum formed and then reinforced on the underside with a thick layer
of fiberglass. It is extremely strong. Even if the acrylic
layer were to crack or blister, a water leak penetrating the
fiberglass would be unusual.
| Acrylic shell cracks and blister voids can be
effectively filled and repaired with
Plast-Aid.
This compound can even be colored with acrylic* artist paints
(available at any art supply store) to approximate the original
color of the spa shell. *do
not use oil based colorants |
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Plast-Aid is a two part product
(filler and hardener) that can be formed, sanded, and polished, and is
the only effective compound available for permanent acrylic shell
repairs that we have found. Unlike epoxy or fiberglass repair products,
Plast-Aid forms a molecular bond with the acrylic shell.
Jet Body - Vessel Leaks
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More often, a vessel leak can
be traced to a bad jet or other shell fitting. Jet bodies
have a flexible gasket which is tightened against the underside
surface of the spa shell. These gaskets can sometimes shrink
or decompose over time, resulting in water loss. You may
have to remove some of the shell's foam insulation to access these
jet gaskets or other plastic fittings such as floor drains,
suctions, etc. |
Make sure
the area is clean and smooth before installing a new component.
After installing and tightening a new jet body or other component,
apply a generous layer of silicone sealant around the gasket perimeter
and fiberglass undershell as an added measure of future leak
protection.
Leaky Wooden Hot Tubs
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There are still a few unlined wood tubs around, so we will
touch on them briefly here. First, it must be determined why
the vessel is leaking. If the tub has leaked since
installation, then the cause is likely improper assembly.
Correction may require disassembly to find and fix the errors made
when it was put together. Refer to the installation manual
and consult with the dealer for help if necessary.
Continue reading if disassembly is impractical. |
Once a wooden tub has been used, it is important to keep it wet.
If the wood is allowed to dry-out, it will begin to shrink (much like
an old wooden boat hull out of water) and this can cause gaps to open
up. Often, refilling it with water and allowing the wood to
reabsorb moisture will cause the gaps to tighten, unless severe
warping has occurred.
If the hot tub has held water without leaking for some time, and
then begins to leak, the problem may be from wood degradation. A
common cause is the use or overuse of chlorine and bromine which
results in delignification, a process in which the wood cells are
actually eaten up. A symptom is the
presence of cellulose fuzz on the tub's surfaces, which can be
removed with a stiff brush.
NOTE: After fixing your
leak problem, consider switching to an alternative
sanitizer such as Cleanwater Blue, which will not attack wood.
Other conditions which may cause leaks are sustained improper water
balance (pH too high or too low), a shifting foundation due to
ground settling, or insect infestation. Carpenter ants, for
example, seek out and devour wet wood.
Household sealants, which are usually solvent or silicone based
products do not work well for this type of leak because they do not
adhere to wet wood. Some tout sawdust made into a paste, then
forced into cracks to help to seal leaks.
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