Multiport, heater and solar valve settings

For normal pool circulation, the multiport valve should usually be set to Filter. Waste sends water out through the waste line. Recirculate returns water to the pool without passing it through the filter media. Backwash and Rinse are filter-cleaning settings. Closed blocks the flow path and must not be used while the pump is running. Always stop the pump before moving the multiport handle.

Filter Normal pool circulation and filtration.
Waste Water leaves the pool through the waste line.
Recirculate Water returns without passing through the filter media.
Closed Do not start the pump in this position.

How pool valve positions change the water flow

Pool valves decide where the pump draws water from and where the water goes after it leaves the filter. An incorrect position can restrict suction, block the return line, send water to waste or direct flow through equipment that should be bypassed.

Pool suction
Pump
Filter
Heater or solar
Pool returns

The suction side normally includes the skimmer, main drain and sometimes a dedicated vacuum line. The pressure side starts after the pump and usually includes the filter, chlorinator, heater, solar plumbing and return lines.

Suction valves These valves control where the pump draws water from. Closing every suction line can starve the pump and cause it to lose prime.
Return valves These valves direct water to the pool, spa, water feature or another outlet. Restricting the only open return line can cause pressure to rise quickly.
Multiport valve This valve sends water through the filter media, around the media or out through the waste line.
Bypass valves These valves direct water through or around a heater, solar system or another piece of equipment.
Before restarting the pump Make sure at least one suction line is open and the return path to the pool is not blocked.

How to switch pool valves before restarting the pump

Do not rotate a multiport valve while the pump is running. Water pressure can damage the spider gasket, rotor and sealing surfaces. Manual diverter valves should also be moved carefully when changing them could temporarily block the only suction or return path.

Stop the pump. Use the controller or time clock. Isolate electrical power as well before opening or servicing equipment.
Wait for the pressure to fall. Check that the filter pressure gauge has returned to zero. Use the filter air-relief valve where fitted. Never loosen a pump lid or filter lid while the system is pressurised.
Move the multiport handle. Press the handle down fully, rotate it to the required setting and allow it to settle firmly into position.
Check the pipes. Make sure a suction line is open and the selected return or waste outlet is ready for water flow.
Restart the system. Watch the pump basket, filter pressure, return jets and waste outlet during the first minute.
Never run the pump with the multiport set to Closed Closed blocks the route through the valve. Starting the pump against a blocked line can cause a fast pressure rise and damage the filter, pump or plumbing.

Multiport valve settings explained

Multiport valves are commonly fitted to sand filters and some DE filter systems. Labels vary by brand, but most valves use the same six main settings.

Setting Where the water goes When it is used What to watch
Filter Water passes through the filter media and returns to the pool. Normal daily circulation and filtration. The waste outlet should remain dry.
Backwash Water flows backwards through the filter media and exits through the waste line. Cleaning sand or DE filter media according to the filter instructions. The pool water level falls while the pump is running.
Rinse Water passes through the valve and exits through the waste line. Settling the filter media and clearing dirty water after backwashing. Rinse is not a normal circulation setting.
Waste or Drain Water goes from the pump directly to the waste line without passing through the filter media. Lowering the water level or vacuuming unsuitable debris directly to waste. The water level can fall quickly. Do not leave the pump unattended.
Recirculate Water returns to the pool without passing through the filter media. Short diagnostic checks or specific water-treatment procedures. The filter is not removing debris in this position.
Closed Flow through the multiport valve is blocked. Only during specific service work with the pump switched off. Never start the pump in this position.

Read the complete multiport valve guide for more information about Backwash, Rinse, spider gaskets and sand filter operation.

Problems caused by an incorrect valve position

Check the valve positions before assuming that the pump, filter or heater has failed. A routing problem can cause many of the same symptoms as a mechanical fault.

Symptom Possible valve-related cause First check
Weak return flow and a pump basket that does not fill properly A suction valve is partly closed, the selected suction line is drawing air, or the heater or solar circuit is adding too much restriction. Stop the pump, fully open a known suction line, bypass the heater and solar system, then restart.
Filter pressure rises immediately after changing a valve The return line is restricted, a spa or water-feature line is selected incorrectly, or the multiport is not seated in Filter. Stop the pump, confirm Filter mode and open the normal pool return line.
The pool level falls only while circulation is running The multiport is set to Waste, a separate waste valve is open, or the multiport is leaking internally from Filter to Waste. Stop the pump and inspect the waste outlet before restarting.
Water circulates but fine debris is not being removed The multiport is set to Recirculate, so water is bypassing the filter media. Stop the pump, move the multiport to Filter and compare the pressure and return flow.
The heater displays a low-flow warning Too much water is bypassing the heater, a return valve is restricting circulation, or air remains trapped after a valve change. Check the heater valve position shown in the manual or marked on the pipework. Confirm steady return flow before restarting the heater.
Bubbles continue after the solar system starts The solar diverter is not fully positioned, the roof circuit has an air leak, or the added restriction is exposing an existing suction leak. Turn solar off and check whether the pool circulates normally.
Water coming from the waste outlet while the valve is on Filter The waste outlet should remain dry during normal Filter operation. Water from this outlet can indicate debris on the valve seat, a damaged spider gasket, rotor wear or internal misalignment.

Use the guide to confirming a multiport valve leak to waste to check whether the water loss is coming through the valve.

Heater and solar bypass valve positions

Heater and solar valves are normally installed after the filter. They control whether water passes through the heating equipment or follows a shorter bypass line.

Three-valve heater bypass

A common heater bypass has one valve on the heater inlet, one on the outlet and one on the bypass pipe. The correct position depends on how the bypass was plumbed and on the heater requirements.

Do not copy the handle positions from another pool Two equipment pads can use the same valves while the pipes run in different directions. Check the valve lid, equipment manual and any labels left by the installer before changing an unfamiliar setting.

Solar diverter valve

A solar diverter sends filtered water to the roof collectors when heating is required. When solar is off, the water normally follows the direct return line. A check valve is commonly fitted to control reverse flow when the roof circuit drains.

  • A short release of air from the return jets can occur while the roof circuit fills.
  • Continuous bubbles, poor pump prime or a large flow reduction should be investigated.
  • Do not force an actuator-driven valve by hand unless the manufacturer provides a manual procedure.
  • Return the valves to their labelled positions before checking an unrelated circulation problem.

Pool, spa and water-feature return valves

Return diverters may direct water to the pool, spa, waterfall or another feature. Sending all flow through a small outlet can raise filter pressure and reduce circulation. After changing the setting, check that the pressure gauge remains close to the normal reading for the pool.

What to do when the valve positions are unclear

If the labels are missing or several valves have already been moved, avoid changing every handle at once. Return the system to a simple filtration setup and check one part at a time.

Set the multiport to Filter while the pump is off.
Fully open one clearly identified suction line, usually the normal skimmer line.
Open the normal pool return line instead of a spa-only or water-feature line.
Bypass the heater and turn solar off, using the labelled positions on the equipment pad.
Restart the pump and check the basket, filter pressure, return jets and waste outlet.
Stop the pump if it does not prime, the pressure rises quickly, water unexpectedly leaves through the waste line or the plumbing begins moving under pressure.

When a pool valve needs repair or replacement

A wrong valve position can be corrected, but cracked valve bodies, worn seals and damaged plumbing need physical repair. Do not keep forcing a stiff handle. This can damage the diverter or crack the valve body.

Internal multiport fault Water reaches the waste outlet in Filter mode, the handle does not sit firmly in position, or the leak returns after the valve has been reseated.
External valve leak Water appears around the shaft, lid, union, sight glass, valve body or pipe connection.
Seized or broken diverter The handle is very difficult to move, turns without changing the water flow or cannot reach the stop.
Poor plumbing layout Equipment cannot be isolated, the bypass creates a blocked line, or new equipment has been installed without suitable valves and unions.

Pool equipment installation

Installation of pumps, filters, chlorinators and heaters with correctly arranged valves, unions, bypass plumbing and startup checks.

Pool equipment installation service

Pool valve position FAQ

Which multiport setting should I use for normal pool operation?

Use Filter for normal circulation. Water passes through the filter media before returning to the pool. The waste outlet should remain dry.

Can I move a multiport valve while the pump is running?

No. Stop the pump and wait for the pressure gauge to return to zero before moving the handle. Changing the setting under pressure can damage the internal seals and rotor.

Why is water leaving the waste line when the valve is on Filter?

The valve may be allowing water to pass internally from the Filter port to the Waste port. Common causes include a damaged spider gasket, debris on the sealing surface, rotor wear or misalignment inside the valve.

Is Recirculate the same as Filter?

No. Recirculate returns water to the pool without passing it through the filter media. The water moves through the system, but the filter does not capture suspended debris.

How can I tell which pipe a three-way valve is closing?

Many valves have an OFF marking that points toward the blocked port, but this is not universal. Check the valve model, lid markings and pipe direction. Once the position is confirmed, label the pipes and take a photo of the normal setting.

Are bubbles from the return jets normal when solar starts?

A short release of air can occur while the roof circuit fills. Continuous bubbles, poor pump prime or a large reduction in flow can indicate a valve-position problem, a solar plumbing leak or a suction-side air leak.

Can Waste mode be used to lower the pool after heavy rain?

It can be used on suitable systems, but the discharge must be supervised. Stop before the water falls below an active skimmer opening, otherwise the pump may begin drawing air.

Filter is the normal multiport setting. Before changing any valve, identify the open suction line, the return line and any waste or bypass outlet. Stop the pump before moving the multiport handle, then check the water flow and filter pressure after restarting.