Hot Tub Spring Startup: Getting Your Tub Running After Winter

March and April are when most Bournemouth hot tub owners dust off their tubs and get them running again for the warmer months. But rushing the startup is the #1 cause of early-season breakdowns — problems that could have been easily avoided with a proper startup routine.

This guide covers the full process for both inflatable hot tubs (Lay-Z-Spa, Intex, MSPA) and hardshell tubs, with specific tips for each.

Before You Start: Inspection Checklist

Before adding any water, inspect everything:

Inflatable Tubs (Lay-Z-Spa, Intex, MSPA)

Check the liner for damage — look for punctures, cracks, or areas where the PVC has degraded over winter. Mice and garden insects can cause surprisingly large holes
Inflate partially and listen — pump some air in, then feel and listen for leaks around seams, valves, and the bottom
Inspect hoses and connectors — rubber seals can perish over winter, especially if stored in a cold shed or garage. Cracked seals = leaks when water goes in
Check the pump unit — look for signs of moisture inside (condensation), damaged cables, or insect nests (yes, really — spiders love pump housings)
Inspect the power cable and plug — any damage, fraying, or discolouration? Don't use it. Get it checked or replaced

Hardshell Tubs

Check the shell — look for cracks, especially around jet housings and the waterline
Inspect the cabinet — remove panels and check for rodent damage to wiring or insulation
Check plumbing connections — unions, valves, and drain plugs can loosen over winter
Inspect the cover — a waterlogged or damaged cover lets heat escape and wastes money all season

⚠️ Don't Skip the Electrical Check If your hot tub has been stored or unused for months, check the power cable, plug, and RCD before plugging in. Rodent damage to cables is more common than people think, and a damaged cable near water is a serious safety hazard. If in doubt, get an electrician to check it — it's a 10-minute job.

Step-by-Step Spring Startup

Step 1: Clean Everything First

Before adding water:

Wipe down the entire interior with a damp cloth (no harsh chemicals on inflatable liners)
Flush the plumbing — on hardshell tubs, use a pipe flush product through the jet lines to clear any biofilm from winter
Clean the pump's filter housing
Discard old filter cartridges — start the season with fresh ones

Step 2: Set Up on a Proper Surface

For inflatable tubs:

Use a ground mat or foam tiles underneath — insulates from cold ground and protects the liner from stones
Choose a flat, level surface — uneven ground puts stress on seams
Consider position: sheltered from wind but accessible for the power cable (which should go directly to an outdoor socket — no extension leads)

Step 3: Fill With Water

Use warm water from the hot tap if possible (max 40°C) — this halves your heating time and puts less strain on the heater
Fill to the maximum fill line (not minimum — you'll lose water to splash and evaporation)
On inflatable tubs, the weight of the water will settle the tub — check it's still level once full

Step 4: Install a Fresh Filter

Always start the season with a new filter. Old filters from last year will have degraded, hardened, or harbour bacteria — even if they look clean. A £10 filter now prevents a breakdown later.

Step 5: Power On — But Don't Heat Yet

Plug in the pump (directly to a grounded outdoor socket — never an extension lead or adapter)
Run filtration only for 30 minutes first — let the pump circulate water and check for leaks
Look for drips at every connection point: hoses, pump inlet/outlet, drain valve
If the pump shows an error code immediately, see our error code guide

Step 6: Add Chemicals

Before heating, get the water chemistry right:

Sanitiser — chlorine granules or bromine tablets. Start with a small dose and test after 30 minutes
pH — test with strips and adjust to 7.2-7.6. Low pH is corrosive (damages the heater); high pH reduces sanitiser effectiveness
Shock dose — a larger initial dose of chlorine or non-chlorine shock to sterilise everything. Run filtration for at least 1 hour after shocking

Don't skip this step. Starting without chemicals means biofilm and bacteria start growing immediately, and they're much harder to clear once established.

Step 7: Start Heating

Once filtration has run for at least 30 minutes with no errors:

Set your target temperature (37-38°C is most common)
Keep the lid on — this is crucial. An uncovered tub loses heat 3-4x faster
Don't run the air bubbles while heating — they cool the water
Expect 12-24 hours to reach temperature from cold (faster if you used warm water)

Common Spring Startup Problems

E02 Error Immediately

The most common spring error. Usually caused by air trapped in the system or a dry flow sensor. Fix: run filtration for 5 minutes to prime the pump, then restart. If it persists, see our E02 guide.

Pump Won't Turn On

Check the obvious: is the socket working? Try another appliance in the same socket. Check the RCD hasn't tripped. If the pump has power but doesn't respond, it may have internal damage from moisture or freezing during winter.

RCD Trips When Plugged In

This indicates an earth leakage fault. Do not keep trying. The pump has moisture inside or a component has failed. This needs professional diagnosis.

Slow or No Heating

If the pump runs but water doesn't heat, see our hot tub not heating guide. In spring, the most common causes are a tripped internal thermostat or failed heater element — especially if the pump was stored in a cold environment.

Cloudy Water After Filling

Normal with fresh tap water — air bubbles and dissolved minerals. Run filtration for 4-6 hours, maintain chemical levels, and it should clear. If it stays cloudy after 24 hours, increase sanitiser and consider a water clarifier product.

Spring Startup Not Going to Plan?

If your hot tub won't cooperate after winter, don't force it — let a local engineer diagnose the issue before it gets worse.

📞 Get a Free Quote

Spring Maintenance Tips for the Season

Test water chemistry weekly — pH and sanitiser levels. Takes 2 minutes with test strips
Change filters every 2-4 weeks (more often with heavy use)
Drain and refill every 2-3 months — dissolved solids build up and can't be filtered out
Wipe the waterline regularly — body oils and sunscreen create a ring that harbours bacteria
Keep the lid on when not in use — saves energy, keeps debris out, reduces chemical evaporation