Maintenance Question How and how often should you clean the strainer basket that sits next to the sand filter?

Blocked or clogged water input line
Sucking air from a leak, not enough water thru system
Excessive debris in strainer baskets
Filter needs to be backwashed
Filter needs new sand or new cartridge
Filter needs to be taken apart and "fingers" cleaned
Filter Pump Impeller is obstructed
Filter motor is in-correctly wired
Filter motor bushings need replacement
Filter motor bearings are worn
Filter motor is "shot"

They are referring to the strainer basket inside the filtration pump, and the pool filter system itself. The indication is either this basket is full of debris or the pool filter is so dirty you do not have enough water flowing through the heater. A safety device in the heater is shutting down the heater to prevent damage. None of the parts you named are inside the heater.

If there is not much pressure, the problem is with the circulation system. Probably the pump.
When a sand bed gets old the pressure goes up on the guage, but the filter doesnt do much. When there is a lack of pressure, its due to a problem with the water flow. Usually a clogged impeller, strainer basket, or skimmer basket.

The most common solution for a loss of pressure is to dissasemble the wet end of the pump, clean out the impeller, and replace all o-rings and seals, including the shaft seal. This will revitalize the performance of your pump.

If sand is getting back into the pool, the strainer in the filter is broken or out of place. The filter has to be disassembled, sand must be removed and the strainer must be inspected for cracks or leakage. New parts are available from most pool supply stores.
Gary

If you need new sink strainer basket for disposal side of sink, you have to buy new disposal.

Each garbage disposal comes with its own strainer basket so that disposal can connect and seal.

First, the disposal strainer basket is installed, and then disposal lifts up and attaches from below.
A rubber gasket comes with new disposal.
Rubber gasket fits between disposal and strainer basket so that disposal seals correctly.

Photo below shows how disposal connects to strainer basket using steel connector ring under the sink.


I wrote tips for installing a disposal from days when I worked apartment maintenance.
http://www.fixya.com/support/r7929008-replace_garbage_disposal

Check skimmers, pump strainer basket and filter pressure. If filter pressure builds. time to backwash the filter. Also, the impellar on the pump might have debris in it...

There is not enough system pressure to close the heaters pressure switch so the heater will not fire. Assuming your pump is on and any valves in your pipes are set correctly it means something is restricing water flow too much and needs to be cleaned to fix your flow rate and allow the heater to fire.

Start at the skimmer(s) baskets and then the pump strainer basket and finally clean your filter. If sand, backwash it. If cartridge or DE clean according to your manufacturers direction. In some cases cleaning a cartridge filter will no longer satisfy heater pressure requirements meaning you will need to replace the element.

If you notice bubbles in the water returning into the pool from the eyeball/discharge, or water in the strainer basket is visibly swirling (bubbles visible) odds are you need you replace the o-ring on the lid of the strainer basket in the front of the pump. This basket may also be clogged with debris, which also effect pressure. Could also be a cracked or warped strainer lid. Should be easy to see when you remove to check o-ring. Once you remove the strainer o-ring make sure you lube it with a good silcone based lube.

Turn the swimming pool pump off and wait for the water to drain from the strainer basket. You want to make sure that the pump is completely off before you proceed. Remove the screws or any items securing the lid of the strainer basket. Open the lid and pull out the strainer basket. Vacuum the strainer basket or scoop out any debris. You may want to run clear water through the basket to ensure you removed all debris. Feel toward the impeller and remove any clogs or obstructions preventing the impeller from working properly. Check the o-ring under the cover of the pump strainer housing. You may need to use a silicon lubricant to ensure a water-tight seal. Put the strainer basket back into the pump strainer housing and pour some water into the basket. Replace the lid and secure it in place. Turn the swimming pool pump on and check for proper pressure. If your pressure doesn't register, you may need to troubleshoot to find the problem.