Well guys I need help and the knowledge of any plumbers in the house or guys who know their way around a oil ( boiler ) furnace.

It's 30 mins. past the witching hour here in frosty Ct. and I had to shut down my furnace at 10pm because the over pressure valve blew and the furnace is just pumping water out of my overflow pipe into my sump when its running.

How much do you think I'm looking at to have the tank and valve replaced if that is indeed the problem?

The Furnace is a Smith Cast Iron Boiler. The Expansion tank is an Amtrol Extrol 12 PSI pre load and 100 PSI max. pressure 240 deg. max. temp.

Here's some pics.

 

Im an oil furnace guy by need, 1 in my house and 1 in my barn. Does the pump run ? You can trip the burner off, then check that.

 

We sold those expansion tanks at Home Depot, when I worked there.

 

ood to know. Thanks Gary.

 

I believe so. The furnace pumps water out of the pressure valve as soon as I flip the switch. The pressure release valve is open constantly. I remember the guy at the plumbing supply company telling me that if that happened then the expansion tank is probably bad.

 

is the water leaking out of tank or just out the valve , you can buy just the Valve for like $30 ish or the kit for $100 ish . My Work Johnstone supply sells them , there might be one local to you but most stores are Wholesale (contractor only)

 

last fall i replaced the tank, fill valve, pressure switch, and pressure pop valves for under $200

 

If it's dumping out immediately then the valve has failed. It's just like a water heater pressure/temp valve, I have seen those go bad and open even when everything is fine.