instant water heater problems

[khunkeith]

we have had a house in THailand since 2006. We have 4 instant water heaters in the house and I am about to replace them for the 3rd time. I have tried flushing them regularly with vinegar to clean out mineral deposits but, even then, after 2 years, they just stop heating the water beyond luke warm. not a problem in the hot weather but, it's a drag on cold mornings.

I see the same water heaters in hotel rooms that look like they have been there for years and the water is still piping hot.

any suggestions or ideas so I am not replacing these things so often? is there a brand available that's really good? or, a way to install an inline filter?

thanks

[IMHO]

You've replaced 12 heaters within 9 years? wow.

If you have an existing tank & pump, you should probably look into a whole house filter that cleans the town water before it even hits your tank. You really can't filter after the pump, or directly filter the mains (in the case you don't have a pump), as it will simply drop the water pressure too much for a quality shower.

With 4 water heaters, you should also probably look into changing it all to solar hot water. In the past 9 years, you've already spent more money than what a solar system would have cost you, and that's not even including how much you've spent on electricity in that time....

[khunkeith]

is there such a thing as a in line filter to attach to the input side? like the in line gas filters for cars?

[Tywais]

is there such a thing as a in line filter to attach to the input side? like the in line gas filters for cars?

The ones I have do have a fine mesh inlet filter on them which I take out and clean occasionally, and especially if the water to the moo bahn is shut off for a period as all kinds of gunk enters when the pressure is back.

[gusG]

What brand are you using?

Do you buy the same brand every time?

[khunkeith]

is there such a thing as a in line filter to attach to the input side? like the in line gas filters for cars?

The ones I have do have a fine mesh inlet filter on them which I take out and clean occasionally, and especially if the water to the moo bahn is shut off for a period as all kinds of gunk enters when the pressure is back.

I have those too. but does not seem to help. I think the mineral build up is due to microscopic particles that form over time.

[khunkeith]

What brand are you using?

Do you buy the same brand every time?

different brands with different wattage's.

[khunkeith]

You've replaced 12 heaters within 9 years? wow.

If you have an existing tank & pump, you should probably look into a whole house filter that cleans the town water before it even hits your tank. You really can't filter after the pump, or directly filter the mains (in the case you don't have a pump), as it will simply drop the water pressure too much for a quality shower.

With 4 water heaters, you should also probably look into changing it all to solar hot water. In the past 9 years, you've already spent more money than what a solar system would have cost you, and that's not even including how much you've spent on electricity in that time....

the house was built with only one water line running through the walls (solid masonry and concrete). putting in an additional like for hot water would mean exposed pipes and we don't want to do that.

We have a water storage tank but, 2 inputs. One from our well and one from city water. We have a piston pump on the well and attach a hose to a fitting on tank.

since I live in the province, finding a qualified expert is not easy.

[RichCor]

I would get the water tested (maybe at the nearest university?) to see what impurities and concentrations your dealing with,

They may advise you to put in a Resin Tank, or other type of filter/treatment system.

Instant water heaters are simple devices. Determining what's happening to them shouldn't be too difficult. Take a useless one apart and see if the heating element is being corroded or impacted by salt/mineral buildup.

Also presuming the following isn't true:

I have no hot water

"If the water is just not as hot as it was earlier, consider whether the groundwater temperature has dropped. Usually this is only a concern to people experiencing their first winter with a tankless water heater. Sometimes, in colder weather, mainly November thru March, the groundwater temperature, meaning the incoming water to the heater, has cooled 5 to 20 degrees, resulting in a lower output temperature. The answer here is to not max out the capacity of the heater. Your heater creates a roughly 50 degree rise in temperature at capacity. So, in cooler months, do not push to capacity. Once the ground warms up, all will return to normal. We suggest people set the temperature to medium during the hot months, and then when it cools a bit, you can increase the temperature to offset the cooler groundwater."

Heater Flow Switch

There is a flow switch that clicks on and off when water starts and stops flowing thru the heater. This is normal and few, as in very few, people ever notice it. But a flow switch making intermittent contact could affect how the heater functions.

Heat Sensor / BiMetallic switch problem

[IMHO]

is there such a thing as a in line filter to attach to the input side? like the in line gas filters for cars?

There are plenty of filter types available, but as I noted already, the pressure drop is very likely to be too much. The best solution is: mains water > filter > tank > pump > house. That's really the only way to have both filtered water and decent pressure/flow.

the house was built with only one water line running through the walls (solid masonry and concrete). putting in an additional like for hot water would mean exposed pipes and we don't want to do that.

We have a water storage tank but, 2 inputs. One from our well and one from city water. We have a piston pump on the well and attach a hose to a fitting on tank.

since I live in the province, finding a qualified expert is not easy.

Of course, the new pipes don't need to be exposed - but that means cutting into walls and replacing tiles - and even that might be hard if you don't have spare tiles, or the same tile can't be purchased anymore.

OTOH, you already have somewhat unsightly water heaters on the walls and if you use Pimaflax Multipipe pipes, what you would see is a relatively nice, glossy white pipe only:

Edited February 23, 2015 by IMHO