Flo control question

[hinow41]

Hey I had a flo control valve fail on me a couple days ago, my house has baseboard heating and heated up when the thermostat was off and the pump off. I replaced the flo control with a regular check valve. Now the hot water seams to be gravity flowing still. What is the difference between the two?
Here is a pic of the flo control that was on the line

This is the type of check valve I installed

 

[Fred61]

Swing check VS weighted check.

 

[Bob Rohr]

A weighted flocheck, or a spring check

Hey I had a flo control valve fail on me a couple days ago, my house has baseboard heating and heated up when the thermostat was off and the pump off. I replaced the flo control with a regular check valve. Now the hot water seams to be gravity flowing still. What is the difference between the two?
Here is a pic of the flo control that was on the line

This is the type of check valve I installed

A weighted flo-check or a hydronic type spring check offer the best shutoff.

Swing checks, maybe if they are in a vertical pipe. Another concern with a swing check is making sure you have enough gpm flow to hold them open or they may clatter. They should be sized by the Cv flow rate, not the pipe size to work properly.

What failed on the weighted Flo-check? it is a fairly simple valve and you could just change out the guts if it developed a leak around the stem seal, for instance.

 

[hinow41]

A weighted flocheck, or a spring check


A weighted flo-check or a hydronic type spring check offer the best shutoff.

Swing checks, maybe if they are in a vertical pipe. Another concern with a swing check is making sure you have enough gpm flow to hold them open or they may clatter. They should be sized by the Cv flow rate, not the pipe size to work properly.

What failed on the weighted Flo-check? it is a fairly simple valve and you could just change out the guts if it developed a leak around the stem seal, for instance.

Well the flo check failed because I over fired the boiler, I went to drop a friend off and when I came back the lines were pissing steam out everywhere and temp was all the way up on the boiler. Lucky for me the pressure valve didn't open and flood my basement. Well I ended up melting the gasket in the old flo control ( I know i messed up bad) I had the other check valve and installed it, seem to be working fine for a couple days but today the water is flowing.

 

[Bob Rohr]

Well the flo check failed because I over fired the boiler, I went to drop a friend off and when I came back the lines were pissing steam out everywhere and temp was all the way up on the boiler. Lucky for me the pressure valve didn't open and flood my basement. Well I ended up melting the gasket in the old flo control ( I know i messed up bad) I had the other check valve and installed it, seem to be working fine for a couple days but today the water is flowing.

Must have been very hot, most hydronic components are rated for 225F temperatures! Maybe the failed pressure relief allowed the pressure to go up, which also changes the boiling point. At 30 psi, for example, the boiling point would be up around 270F.

Replace that relief valve, and be sure it has adequate protection, most valves show a pressure, and BTU/hr rating. Can you run the relief valve discharge to a drain or sump pump? There is an incredible amount of energy potential in steam, better safe then sorry.

 

[hinow41]

I got a new Flow control and installed it today everything is working fine now. Had a friend that is a boiler mechanic look everything over for me. Thanks for the replies

 

[maple1]

I think I would concentrate on finding how you had such an overheat. There should be fail-safes in place to avoid that situation happening.

 

[hinow41]

I think I would concentrate on finding how you had such an overheat. There should be fail-safes in place to avoid that situation happening.

What test can I do to find out what is/did fail?

 

[Bob Rohr]

Y

What test can I do to find out what is/did fail?

You mentioned that you "over-fired" the boiler??

Does the boiler have a means to shutdown when it reaches a high limit temperature?

Fossil fueled fired boilers have a gas valve, or solenoid valve the shuts off the fuel supply. Wood fired usually have a fan and or draft door. Determine which you have and test the operation.

All pressurized systems need a pressure relief valve PRV. A 30 psi relief valve is common on residential systems, and they are generally screw right into the boiler block somewhere. Never use a water heater type PRV on a boiler, the pressure rating is much too high. It is a common mistake to confuse relief valves for boilers and water heaters.

Really, any time one discharges it is a wise idea to replace the valve.

Find out what controls the burner or fire, and check and replace any safety relief valves with the correct valve.

And watch the MythBuster episode that shows what happens when a water heater flashes to steam with a defective relief valve

 

[hinow41]

Y



You mentioned that you "over-fired" the boiler??

Does the boiler have a means to shutdown when it reaches a high limit temperature?

Fossil fueled fired boilers have a gas valve, or solenoid valve the shuts off the fuel supply. Wood fired usually have a fan and or draft door. Determine which you have and test the operation.

All pressurized systems need a pressure relief valve PRV. A 30 psi relief valve is common on residential systems, and they are generally screw right into the boiler block somewhere. Never use a water heater type PRV on a boiler, the pressure rating is much too high. It is a common mistake to confuse relief valves for boilers and water heaters.

Really, any time one discharges it is a wise idea to replace the valve.

Find out what controls the burner or fire, and check and replace any safety relief valves with the correct valve.

And watch the MythBuster episode that shows what happens when a water heater flashes to steam with a defective relief valve

I have an old wood boiler, the over fire happened I left the front air intake too far open. From what iv seen the only time the intake operates its self is if the boiler gets too cold. When I damp it down for an overnight burn the intake is almost closed all the way. In the morning it will be open more to keep the fire going.
I do have a relief valve on the back of the boiler.

 

[maple1]

There should be two things that happen if a boiler gets hot. First, the draft door should close completely when the boiler reaches its hot temp, say maybe 190. Then if the temp keeps climbing, it should dump the extra heat to a dump zone - typically using a normally open zone valve wired to an aquastat that cuts the power to the zone valve when it gets above setpoint (say maybe 200). When that zone valve opens, it also turns on the circulator pump. That setup also serves to help dump heat in a power outage - when power goes out, the zone valve opens & the water can circulate by convection. The dump zone should be elevated above the boiler for it to convection good. We still don't know much about your boiler, but the draft door (intake) shouldn't close almost closed - it should close tight. Another measure of protection is the pressure relief - it should blow off when system pressure gets too much (typically 30 psi). If you keep a regulated fresh feed hookup in place (I believe a coded practice), then at the same time the relief blows off, it will allow cold fresh water in to replace it. All three of those things should be in place - there is not much substitution for redundancy when it comes to wood boilers.

 

[hinow41]

The boiler I have is a Burerus Logano. When I say the draft door closes I close it at night to get a longer burn. Thats what the Burerus says in the manual. Here is a pic of the boiler, The part i have been referring to as the intake or draft door is that vent on the bottom door that's attached to the chain.

When the boiler hits 190 the pump does kick on and circulate the water into the baseboards in the house. When my over fire happened it may not have hit the 30psi mark. I have two maid-o-mist on the lines that auto release some of the pressure. I wish I could explain these things better, I'm still learning how these systems work.

 

[maple1]

Closing down manually to get a longer burn seems to me to be a stove operating procedure that shouldn't be applied to boiler operation. I'm surprised that would be recommended in a boiler manual. That bottom draft door should open and close with falling and rising boiler temps on its own and not rely on any manual intervention.

 

[hinow41]

This is what the manual says
In constant heating mode, the
boiler can be operated for
twelve hours at a reduced heat output.

4.7 Constant heating mode
(fire continues burning overnight)
In constant heating mode, the
boiler can be operated for
twelve hours at a reduced heat output.
Adjust the boiler settings
as follows for constant heating
mode:
V
Stoke the fire and completely fill the fuel feeder box
(split wood).
V
In order to reduce the combustion air intake, close the
air vent almost completely.
V
Open the exhaust flap.
This way, the formation of tar and soot accumulations
in the flue gas system are reduced during constant
heating operation.
V
Set the return temperature booster on the mixing valve
so that the boiler water temperature rises to between
176 and 194 °F.