KA-6 losing Domestic water temp

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NEWBIEonDUTY
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Post by NEWBIEonDUTY » Fri. Dec. 03, 2021 7:44 am

Hello-

I have a question I was hoping someone can help me with. I have had my boiler since 2017 and it has served me well. I run it year around to provide heat as well as domestic hot water. Lately we have started to notice that even with the boiler in the 170-180 range we have to turn the shower all the way to hot to get even luke warm hot water. This issue seems to be getting worse and I think it's time to address.

I have a mixing valve on the hot water discharge that is culprit #1. I went down there last night to adjust it, but to my dismay it is already turned to the hottest allowable setting. I realize these can go bad an am willing to replace it, but before I did I wanted to stop by here to ask about the possibility that my domestic hot water exchanger could have a scale build up causing my issue?

I have well water as well as a water softner. Is it a possibility that I have scale and if so, do I just remove the coil and dip it in a scale remover?

I am not sure of any other possibilities and was hoping someone here has dealt with a similar situation that could provide some insight.

Thank you to anyone who takes the time to read this and respond, this site truly is the best place for information on these boilers!

 
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tsb
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Post by tsb » Fri. Dec. 03, 2021 8:12 am

Is the water going to the mixing valve hot ? Can you check the flow and temp before the mixing valve ?
Can you kill the cold going into the valve and check the flow of just what's going through the boiler ?
As you can imagine, my thought is the mixing valve.

 
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franpipeman
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Post by franpipeman » Fri. Dec. 03, 2021 8:19 am

The coil need to be cleaned or that is the passages INSIDE the coil , if a coil is used need to have a delimer or anti calcification pumped through it clean the scale our even vinegars. . Of course the mixing valve could be bad, Im also not knowledgeable about the ka6.Not all coils are piped properly to clean out conveniently and may need to be installed. fyi




https://www.supplyhouse.com/Oatey-35230-Haymaker- ... EmEALw_wcB


 
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McGiever
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Post by McGiever » Fri. Dec. 03, 2021 8:32 am

Since in service continuesly since 2017 your are due to give both the coil and mixing valve some TLC.

As was said if plumbed properly from the beginning then all the fittings and valves will be in place to set up a convient acid flush.
As for the mixing valve it will need removed and soaked or perhaps a rebuild kit could be available???

 
NEWBIEonDUTY
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Post by NEWBIEonDUTY » Fri. Dec. 03, 2021 8:53 am

When I get home from work I am going to start with the mixing valve based on what I am reading. The video linked above states that he had low flow/pressure due to the coil being plugged, which makes sense. I don't have any issues with flow or pressure, so I believe this points more to an issue with the mixing valve then it does a scaling issue with the exchanger. I will report back this weekend with my findings. Thanks again

 
Kungur
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Post by Kungur » Fri. Dec. 03, 2021 9:54 am

Thanks!! This served as a reminder to do mine!!


 
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Rob R.
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Post by Rob R. » Fri. Dec. 03, 2021 10:37 am

Mixing valve is primary suspect. What model is your mixing valve?

 
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McGiever
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Post by McGiever » Fri. Dec. 03, 2021 10:58 am

Mixing valve performance restored would get you immediate improvement and a happy family as for water temperatures. However not a good idea to wait until hot water coil shows reduced performance to then try to get it back to near new condition.

Hope it all works out well for you!

 
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franpipeman
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Post by franpipeman » Fri. Dec. 03, 2021 2:02 pm

I was never a fan of the wax operated tempering dhw tempering valve .they seem to have had for me a limited life span and erratic operation.Inin institutional hvac /pliumbing they would have motor operated tempering valve. Yes more complex and expensive but better . What are the being used in the residential field now?

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