Hot water is only warm, help!

[louballs]

Hello,

I did a search but could of find this exact problem. We have an oil hot water heater (pic attached) which feeds the bathroom, kitchen, and radiators. I noticed this morning in the shower that the hot water was not that hot. I was able to turn it up all the way and not get burned. I checked the kitchen faucet and it's the same. I thought maybe the heater wasn't turning on but after running the water bit I heard it kick in. The thermostat is a bit over 145 degrees. I also opened up the drain valve into a bucket and the water coming out of the heater itself was scalding. So it seems that somewhere after the heater something is messed up, but since i'm not well versed in plumbing I don't know where to start. I would love to fix it myself if I can. What would cause the water in faucets, shower, etc. to be warm when the water I the tank is Hot? Thanks for any help!

Lou

 

[Mr_David]

What you need is a manufactures manual. They usually have a troubleshooting guide that can walk you through diagnostic.
Look for one online maybe you'll get lucky.

 

[Mr_David]

This looks like a thermostatic tempering valve. it mixes hot/cold water to to give you the desired temp.. The boiler water temp can fluctuate as it is heating. this valve controls the temperature so it is a constant safe temperature. Probably need to replace that

 

[louballs]

Thanks, i thought that might what that was for. I haven't touched it since I moved in to this place (2.5 years ago), so maybe it just failed?

 

[Matt30]

Have you noticed a drop in pressure on the hot side?

 

[louballs]

Yes I noticed a bit of a drop.

 

[Matt30]

The heating coil in the boiler may need replacing. They are prone to plugging up over the years with dirt/sediment. Generally you notice a pressure drop on hot side, and a decrease in water temperature.

May be best off to have a professional come in and diagnose on site. This could turn into an expensive guessing game for you.

 

[louballs]

But when I run the purge valve from the boiler it is scalding leading me to believe it wouldn't be that, right?

 

[Matt30]

I don't see the valve you're talking about, sorry. Small screen. Anything on the boiler side will be scalding yes. 2 separate systems. The coil has an in/out. Cold water goes in, hot water comes out going to your mixing valve. Is there a drain before the mixing valve?

 

[frodo]

http://newyork.cbslocal.com/2014/03/14/thousands-of-boilers-recalled-and-homeowners-may-not-know-it/

 

[Mr_David]

Unless you need really hot water for anything else turn down the thermostat on the htr to 130 F. Tempering valve has probably seized up and not allowing the desired mix. hot in one side cold in the other Just right out the bottom