diyhome
New Member
Hi. I have an old Aquastar 240FX tankless water heater.
The unit is old but mostly works OK. Lately it has developed the annoying habit of "temperature surfing". Once the water is hot and you're taking a shower, the water will get cold for a while, then heat up again. This cycle will continue. The time between hot to cold to hot again is maybe around 3 or 4 minutes.
Does anyone have any suggestions for what the problem is?
It might be relevant to add that AFAIK the unit has *never* been descaled. When the unit came in to my possession, it was probably already 10 years old, and hadn't been serviced. A repair guy who fixed the unit after the igniter failed, recommended that I not start descaling the unit. He said that if it had not been regularly descaled in the past, that descaling might cause it to leak. Better to just leave it. The water (Los Angeles) isn't super hard but I do find limescale when I flush my coffee machine boiler.
Thanks!
The unit is old but mostly works OK. Lately it has developed the annoying habit of "temperature surfing". Once the water is hot and you're taking a shower, the water will get cold for a while, then heat up again. This cycle will continue. The time between hot to cold to hot again is maybe around 3 or 4 minutes.
Does anyone have any suggestions for what the problem is?
It might be relevant to add that AFAIK the unit has *never* been descaled. When the unit came in to my possession, it was probably already 10 years old, and hadn't been serviced. A repair guy who fixed the unit after the igniter failed, recommended that I not start descaling the unit. He said that if it had not been regularly descaled in the past, that descaling might cause it to leak. Better to just leave it. The water (Los Angeles) isn't super hard but I do find limescale when I flush my coffee machine boiler.
Thanks!
