How to adjust Gas water heater?

mmm technology, or Living in Taiwan? - feel free to move it

10: I have got a gas powered water heater that works fine for about 5 mins, then the flame goes out making it cold. A quick shut off of the water at the shower and back on again gets the flame going again, but of course I have 2 mins of cold to get thru to get to the hot water again.
Goto 10:

yes, this keeps cycling which is annoying. 3 shut downs in 10 mins and half of it cold makes for a grumpy start to the day.
Anyway, on the water heater are 3 things I can fiddle with 2 control knobs and a D cell battery, and they are labled in chinese, along with some other writing in chinese.

I’ve figured out that one knob controls the temperature (or gas flame), and the other one controls water flow, but I’m not sure what sort of flow it controls: overall flow thru the heater, or the flow at which the gas ignites? I have fiddled with the flow thing a bit and I can’t seem to find a place to leave it set that will provide a simple thing: uninterrupted hot water in summer AND winter.
Sometimes I get it to work OK for a month or two, then as the season changes (therefore source water temp hotter or colder -> the temp control in the shower is altered to maintain normal shower temp) then it craps out again.
I have replaced the D battery with a new one too, btw.

Any tips appreciated.


This may sound like a stupd idea but as I have had the same problem in the past (many times), here’s what works for me:

First, the problem may not be your water heater at all! I have paid people to come out a look or "fix: the problem but it was my cleaning person who did this and done periodically, it works. Check your taps - all your taps. Remove the little screw - on thingy where the mesh trap is, at the end where the water comes out. You may see sediment of various kinds - mine is usually little white calcium stones. Rinse the little thingy, making sure that you have gotten all the sediment out. Use a brush if need be. Replace the little thingy on the end of the tap. Do this regularly with all your taps, not just your hot water taps.

Apparently, the problem is that this sediment buildup blocks the pressure of the water so that it is not continuous, thereby stopping the water heater from working effectively.

I thought it was nuts at first, but it does work. If this doesn’t solve the problem I guess calling a gas person in is the next step. This is free, though, and worth a shot.

Thanks for that.

btw, there is no such thing as a stupid idea IMHO

I had the same problem, but when I switched the tanks everything went back to normal. (yes, if you can believe it my apartment still uses tanks!)

totallytika has the right idea though, clean all the crap out of the faucet nozzels and see what happens.

yeah, thinking about it I reckon there is some clue there.

I think those water heaters have a safety mech that turns of the gas if the temp/pressure buildup inthe unit gets excessive. If the flow of water going thru the system(and hence the heater) is restricted by either a low flow at the tap or build up of shit, then the safety mech cuts in to stop the unit from overheating the water -> exploding the unit -> exploding the house.

So, the flow/temp I adjusted in the unit to get it to work in winter is now out of whack cos the relative flow of the hot water in summer is less than in winter, thereby causing the low flow safety mech to kick in.

What I think I need to do is:
Check the nozzle screens for buildup, AND
Adjust the unit so the output temp is lower and thereby resulting in more hot water flow at the shower (i.e. less cold water needs to be mixed in)

Sound plausible?

The 2 controls are like this…

Gas/flame: This controls the flame size and hence the speed at which the water heats, i don’t think it really has a temperature control, but based on the speed of cold flowing in/hot flowing out the temp is somewhat regulated. The cut-off (safety) happen when the water temp inside gets too hot… it waits for it to cool and then should start up again… but usually doesn’t, thats why you stop/start to begin heating again.

Water flow: This detects when water is flowing through the system and turns the unit on, if the water pressure of your apartment is too low you may need to adjust, but as long as you hear the clicking sound when turning on the hot tap you should be fine.

Battery: That is just used for the spark to ignite the flame, poor spark can cause problems because if the gas does not ignite quickly warming a sensor the unit will also shutdown… so keep the battery fresh.

I guess what you are seeing is being summer you are using less hot water, as the heater is on over time the water inside continues to heat (more so as you are using less) until it trips the cut-off (over temp).

To over come this you should be able to turn down the flame, this will stop the over heating… the adverse effect this will have is initially the water will take longer to get warm… :fume:

The things are fiddly so take a bit of tweeking

::edit:: Should also mention not only are you using less hot water, but the cold water coming in is warmer so heats quicker compounding the problem.

Try my technique:

The reason for the internittent hot water is due to pressure variations where the water pressure goes below the min. required for the heater. This often happens to apt’s where a pump with a pressure switch (and/or accumulator) are involved. Pump running = hot water; pump off = no hot water. The trick is to get the pump to run all the time while you’re showering.

  1. Turn water heater as hot as it’ll go
  2. Turn on shower hot water as as high as it can goe
  3. Tunr on cold water as high as it can go
  4. Turn on hot water for the nearest sink - use this to modulate the temp.
    of your shower - the sink will draw down the supply of hot water
  5. Increase the sensitivity of your water heater if its got that know, not all do - some just have a combined temp adjustment (buy the ones with both)

Works like a charm once you’ve got enough water flow going. A little wasteful though

In all my time I cannot remember ever living in a place that had a shower that consistently worked.

In our current house we have the flame as low as it will go and it is still too hot to use. We only have one pump which certainly effects the water pressure. When the water pressure is “normal” in our neighborhood the shower is quite ok but the water pressure here is seldom good.

I can’t believe the amount of water we waste trying to get a quick 5 minute shower.

I’ve had that problem and connel is right. In summer, you need to turn the flame down.