Pilot does not spark to ignite flame for pilot

Not to sound silly, but are you pushing the igniter button down hard enough so it snaps? If so, your igniter is no good. Try to light the water heater the old fashioned way by using a match. I would use fireplace matches since they are long enough to reach the pilot light point.

Sounds like an old boiler. It is not on timer and has to be lit manually. Push in the gas button and hold and push the sprung ingnition button to greate spark. Continue to hold in gas button 1-2 mins and release. The pilot light should then stay on. The flame will have heated the sensor in the combustion chamber and the boiler thinks that there is a flame and will allow the main gas jets to light when demanded . If the flame does not stay on clean the sensor prongs with emery cloth but do wait until they are cooled. You have open up the combustion chamber for access
The 1-2 mins above varies

Pull out sparking rod and lightly polish with fine steel wool. then put back together. Could be in control box but I doubt it. You will probably see mild corrosion on rod.

Hold in your pilot button, then push the spark button repeatedly to light your pilot. Once its lit, hold that pilot button in for 30 seconds to heat your thermocouple. once its heated, release the button, and slide the slider to burner position. Turn on hot water fixtures to get the unit to light

assuming you mean you have electric ignition, DO NOT try to lite with a flame of any kind. make sure gas is on, while pushing knob turn to PILOT hold knob down for appr. 10 seconds while still holding knob down,push ignter. you may have to do this proccess afew times. if this doesnt work, call a pro. gas appl. can be extremily dangerous

Check the pilot is clean not a short flame so its missing the sensor. Also check flame sensor and connection .

You may have a plugged orifice in the pilot tube assy. If you have any way of getting to the orifice with compressed air, and blow back, it may dislodge it, if it is plugged. If possible, carefully remove pilot tube at valve end first, so that if it is debris in there, it blows clean of the tube, so it won't clog again. Otherwise you'll have to remove complete assy. Another thing to try as well, is to shut valve off, loosen fitting at valve for pilot tube, AND MAKING SURE NO FLAME OR SPARK ANYWHERE IN THE AREA, take a spray bottle with dish soap and water mixed (bubble tester) and then spray at pilot fitting when it is loose, and push pilot, to see if any bubbles appear, indicating gas flow. If no flow there, then I'd get a new gas valve.

no gas is getting to pilot light. if all else fails change thermal coupling, if this is bad no gas will come out.

In general, large button from gas valve push in & hold 20-30 secs at same time push electronic lighter/ignition button to light pilot. Remember to hold in only gas button. the pilot light heats up a thermo couple [u can see this in the flame] and when hot enough allows the main gas through and the pilot to remain on.
If not then either thermo couple not heated for long enough or
it may need replacing

First check your gas supply, gas in bottle or lines? I know, this is basic & I'm not having a shot at you, but you'd be surprised at how many times it gets overlooked.

If you do still have gas supply, evident by that low hiss when you hold the pilot feeder button in (you might have to lean in close to hear it), then you need to check that the piezo is working. This is the bit which produces the spark to ignite your pilot. You will be able to see it sparking at the pilot outlet when you push the button (if you're looking in the right spot).

Ok, you have gas & a working spark? Not sure which buttons to press?

You mentioned the manual no longer being in a helpful condition...do you know which of the 4 buttons, 2 taps, 1 slide control & 1 dial do what?
Well just in case, here we go in simple form... first button on the left is the pilot feeder (lets gas through the pilot), second button from the left is the 'ON' button, third from left is the 'OFF' button & the fourth from the left is the piezo ignite button (gives you that much needed spark!). The slide controls your flame (how much gas gets fed to it). The dial, below the pushbuttons & slide, controls how much water flows through the system which then helps regulate the heat. Make sure the taps on your gas & water lines to the unit are on. There you go...2 taps = gas & water supply, 4 buttons = pilot gas, on, off, piezo (spark), 1 slider = gas/flame control, 1 dial = water flow control.

Ok let's see if we can light it! Water & gas supply turned on, slider set about 25% from left, dial set roughly in the middle, push in button 1 (1st from left) & hold in for about 10 seconds, you should hear a very faint hiss from pilot area. Yes? OK, keep holding button 1 in & press & release button 4 several times until pilot lights, you may not see a difference but if you can't see it and it does light you will hear the faint hiss change to a soft fluttering sound as the flame consumes the gas. Still OK? if so then the next step is to push in button 2 quite firmly & then release button1 as well. If all works as planned you will shortly have hot water supply restored.

If the above has not worked then your hot water service may just need a service to clean everything up & maybe replace a few worn or excessively corroded parts. Otherwise ,if there are no blockages in supply lines etc, then it may be time to replace it.

You neglected to say how long you've had it.

Cheers, hope this has helped.

Dennis