Water heater question

Thanks in advance for your input.
I have just replaced my gas water heater.  But both my old and new one has an interesting problem: the water coming out of the water heater has different temperature on different days.
I have not changed the setting on the water heaters.  the water comes out of the same location in teh house.
It happens 10% of the time.  What I mean is: on 10% of the days, the water coming out would be much cooler than on other days.
I cannot think of any reason other than that the gas coming in is weaker?  Does not seem right. 

所有跟帖： 

• 不懂，这种情况下我一定马上叫人来修。 -3apples- ♀ (0 bytes) () 08/20/2014 postreply 18:12:45

• 我这两天也这样，估计里面有水垢需要放一下水。 -borisg- ♀ (0 bytes) () 08/20/2014 postreply 19:03:20

• 给你抄来一段书：） -瞎问瞎说- ♂ (676 bytes) () 08/20/2014 postreply 19:10:08

• 将温度调高点，试试。水厚是放不掉的。再着，新的也不会有水厚的。 -pssci- ♂ (0 bytes) () 08/20/2014 postreply 19:27:20

• Thank you -joeyli- ♀ (136 bytes) () 08/20/2014 postreply 20:00:23