Hi I have the mixing valve open all the way and I still run out of hot water very quickly. I was wondering if I need to get a plummer to replace this or can an oilman figure out what is wrong.
Thanks

Hi Pekeanje

First thing to do in this case is to try and replace the mixing valve ELEMENT (see 1st image)... will allow you to set a safe water temperature.

The next step will be to determine if the heating coil is getting clogged up as this is what determines how much hot water you get... not the mixing valve. If the coil is getting clogged a qualified plumber can do an ACID WASH of the coil and see if that improves things.

You could also have a Watts P-3 valve (other image) installed in the cold water supply to the tankless coil. This handy little device reduces the volume of water delivered to the tankless coil so it can be heated properly WITHOUT affecting the pressure of the system. This is cheaper than an acid wash and something I have installed many times with great success, OK?

You can only find the P-3 valve online or at a local plumbing supply store.

Back to you...

Mark

Thanks for the reply Mark. I had a look at my furnace and I don't see either the valve or the watts P-3 the pipe from the furnace is warm but after the mixing valve it is not. The temperature on the furnace is 170 but the pressure is at about 5 earlier it was at about 20

I didn't suggest that you would have a P-3 valve... suggested that you may want to get one installed... ;)

In terms of the element I posted a picture of, it is INSIDE the mixing valve so you wouldn't see that, either!

Temperature on the furnace at low limit should be about 170F and at high limit about 190F during the winter. During the summer/spring the high and low limits can be set to lower temperatures when you know how to do that!

Water pressure of the boiler should be at about 12-15 PSI and your autofill should really have taken care of that! This would NOT affect how much hot wtaer you get.

Sounds to me like you need to get a qualified tech. in and have him look at the boiler fill valve, the mixing valve (and/or replace the mixing valve element), AND maybe install a P-3 tankless valve.

Talk to the tech about how to set lower temp. limits (high and low) during the summer... can save you money down the road!

Let me know what happens, OK?

Ok thanks for the help. I will call a plummer tomorrow and let you know what happens.