Ask Experts Questions for FREE Help !
Ask
    kcoryer916's Avatar
    kcoryer916 Posts: 2, Reputation: 1
    New Member
    		  
    #1

    May 6, 2007, 08:58 AM
    Very little hot water
    Trying to figure out why the hot water comes out of the taps scalding hot for about two minutes and lukewarm at best after that. After some research I decided it was the tempering valve. When I went to look I could not find one. We have a tankless hot water boiler, HB Smith FD12-W-5. I found the manual and there IS one in the diagram but like I said for the life of me I cannot see it. Can I install one if it's not there. If the tempering valve is not the problem what else should I be looking at? Thanks in advance for you help.
    hvac1000's Avatar
    hvac1000 Posts: 14,540, Reputation: 435
    Heating & Air Conditioning Expert
    		  
    #2

    May 6, 2007, 04:30 PM
    Possible scale in the heat exchanger.
    JackT's Avatar
    JackT Posts: 260, Reputation: 19
    Full Member
    		  
    #3

    May 6, 2007, 05:00 PM
    How old is your boiler? If you have a tempering valve, I don't believe that's your problem. I agree with hvac1000 that you probably have a scale problem in your heat exchanger. Over a period your heat exchanger will build up a white scale on the inside of the pipes. This scale acts as an insulator slowing down the process of heating up the water. The water that's just sitting in the exchanger is hot but, as soon as you open up your faucet, the boiler can't heat up the cold water fast enough and as a result you'll get only warm water. Depending on the age and condition, you may find someone who can circulate acid cleaner through it that will remove the scale. Or it may have to be replaced.
    kcoryer916's Avatar
    kcoryer916 Posts: 2, Reputation: 1
    New Member
    		  
    #4

    May 6, 2007, 05:46 PM
    Quote Originally Posted by kcoryer916
    Trying to figure out why the hot water comes out of the taps scalding hot for about two minutes and lukewarm at best after that. After some research I decided it was the tempering valve. When I went to look I could not find one. We have a tankless hot water boiler, HB Smith FD12-W-5. I found the manual and there IS one in the diagram but like I said for the life of me I cannot see it. Can I install one if it's not there. If the tempering valve is not the problem what else should I be looking at? Thanks in advance for you help.
    The boiler was installed in 88' so maybe it is time for a new exchanger. Thanks.
    labman's Avatar
    labman Posts: 10,580, Reputation: 551
    Uber Member
    		  
    #5

    May 7, 2007, 04:22 AM
    So much for the supposed longer life of the tankless heaters.
    hvac1000's Avatar
    hvac1000 Posts: 14,540, Reputation: 435
    Heating & Air Conditioning Expert
    		  
    #6

    May 7, 2007, 04:25 AM
    Here is a web site for your replacement coil.

    HB Smith - Tankless Heaters Replacement Coils
Not your question? Ask your question View similar questions
 

Question Tools Search this Question
Search this Question:

Advanced Search

Add your answer here.


Check out some similar questions!

Diverter valve leak - 3 valve diverter valve? [ 1 Answers ]

My shower has three knobs and the one in the middle diverts the water flow from the tub spout to the shower. I think that means I have a 3 valve diverter valve, if not please correct me. When I turn the diverter knob so that the water comes out of the shower, there is still significant water...

Three valve diverter valve [ 1 Answers ]

On the three vlv diverter, I've removed the diverter stem, but I'm not sure how the seat comes out. If it screws out, do you have to have a special tool for that or can I improvise?

Smart valve [ 2 Answers ]

Hello, I have two questions. I have a Tempstar gas furnace that has a intermittent smart valve issue. It sometimes goes days and works fine and others, it will not open the main gas line. I get an orange glow from the ignitor, but the gas never comes on and the cycle ends after a few tries....

Gas valve noise on main valve engagement [ 1 Answers ]

I have a carrier 58gs100ga furnace with a white rodgers 36e93 gas valve. The main gas valve solenoid chatters or rattles for a split second before it stays engaged after the pilot is proved. I just replace the spark/lock out board and the fan board for a different problem. This chatter is...

View more questions Search