MIxing valve

weedhopper

So we are replacing our boiler with a direct replacement slide in swap. I want to replace the hot water mixing valve but cannot find this configuration on the Supply House site. Nothing on Google. Is this an old style? It seems to work fine but it’s 24 years old and I figured it would be a good idea to replace it. That crooked soldering job has always bugged me although it has never leaked.

Any suggestions concerning brands ?

As always thanks for the help !

weedhopper

^^^ Ps The “off” tag is for something else. The main supply to the boiler. Looks like the mixing valve though.

STEVEusaPA

It just a standard valve used to throttle the cold water for mixing, handle missing/broke off.
Cut it all out and replace it with a proper lead free mixing valve, properly piped.

weedhopper

OK. Question part B. Do I need the valve with the red handle? It has never served any useful purpose, to me at least. Is it just a domestic hot water valve for convenience? It’s higher than the coil so it’s not a drain.

If no need for it I will just eliminate in when I replumb.

mattmia2

Is there a relief valve on the hot water side of that coil somewhere? Did someone replace the relief valve with that boiler drain?

weedhopper

No relief valve for domestic hot water. There is one for the heat. That drain was original , installed with the boiler. I opened it once and had a heck of a time getting it to stop dripping when I shut it off. I want to eliminate any possible potential problem or leak.

Do I need a relief valve for the domestic hot water ?

SuperTech

You should have a temperature and pressure relief valve on the hot water coil. A T&P valve is different from the pressure relief valve on your boiler.  It is required in some areas, but most boilers that I see with a tankless coil don't have them. 

SuperTech

Its also a very good idea to have isolation valves and drain valves installed on both sides of the tankless coil.  This will enable you to be able to de-scale the coil in the future. 

weedhopper

OK. I see some at Supply house for water heaters but not the kind that would solder into the system.

SuperTech

You would have to buy some fittings and pipe in a 3/4" female adapter 

Think about how that drain valve is piped in in your pictures above. The T&P would be installed in piping like that. 

weedhopper

OK. I am going to run to Home Creepo and touchie feelie. Supply House is great but as an amateur I need to see the stuff. My job is to gather the parts and the pros will come and put it together.

mattmia2

you can buy like 5 fittings and have options from supply house for what one will cost from home depot...

weedhopper

Home depot was a joke. I should have known. So I have an order brewing with Supply House.

One thing I can ‘t find is the 1 1/4 x 1 1/4 flange. Not at SH or google. Always throw me back to 1 1/4 x 1”. I know it exists because there is one on the existing boiler.

mattmia2

Which fitting are you looking for? That propress adapter in the foreground or that reducer screwed in to the boiler in the background?

weedhopper

The reducer going in to the boiler. Both sides are 1 1/4

weedhopper

OK, I made a mistake. The boiler takes a pipe ( for measuring purposes) 1 7/8 OD. The piping from the boiler is a bit smaller, 1 5/8. So they are not the same size.

weedhopper

So I am thinking this is it ?

mattmia2

Yeah. that is not possible. it is probably a 1.5" x 1.25" reducing bushing

weedhopper

Probably and thanks. ID is about 1 1.5. It’s worth a shot at 5 bucks.