Mixing Valve question

[warrenbrown]

I selling my Dad's house, the buyer's inspector noted that in the 2nd floor bathroom turning on the shower or bath tub and the bath room sink water would stop flowing in the sink. Turning off the shower caused flow to return to the sink but scalding hot. The flow issue was the water filter clogged somewhat but since the water pressure is 25 to 45 psi and the entire house is 1/2" pipe the flow is poor. Now that buyers want a statement from a plumber saying that it is not a safety issue. The boiler which has a tankless coil in it is set at 180 with no mixing valve to regulate temperature. Somehow I doubt a plumber would would agree 160+ water is safe.

My question is: Do mixing valves mounted on the boiler domestic hot water outlet affect the total flow?

Warren

 

[Caduceus]

A tempering/mixing valve typically doesn't have a noticeable affect on the pressure or volume.
You might want to consult a plumber familiar with the local codes to do an on site inspection of what you need. In my opinion and in my experience with houses being sold/transferred, these things can be frustrating when handled solely by the seller. You are dealing with a home inspector who may or may not become a challenge for you. You need another pro, but in your corner. The buyer wants statements from people...which translates into "If something goes wrong, this is who I'm suing." Have an insured professional fix all safety issues.
Things aren't as simple as they used to be and if an honest tradesman can come in and nip it all in the bud fast then you can continue on with the sale.

 

[warrenbrown]

Thanks for the input. I have a licensed plumber friend of the family that I have called earlier tonight. He hasn't returned the call yet. Either he or the licensed heat and refrigeration guy is going to do the work. I'm trying to arm myself with as much info as possible. I'd hate to pay to have something installed and then find nearly no flow upstairs.

I recall as a kid my Dad would turn down the boiler after the yearly service to minimize the extreme HW temperature. The right solution I think is a mixing valve but don't want to create additional problems.

Warren

 

[lordofthepipes]

a mixing valve in that application wont reduce flow.