Boiler fill Hot Rod

cutter

Hot Rod, I have followed the pictures from idronics #10 page 29 figure 6-14. How does the boiler fill when piped like figure 6-14? The fill water enters on the return header next to the separator it goes through the return of the separator to the boiler return. Between the boiler and the return header is the Thermostatic anti-condensation valve. That valve prevents any water below 140* from going to the boiler. On the boiler supply side water leaving the boiler passes through a check valve. That valve prevents any water from getting to the boiler on the supply side.
The picture shown of the automatic fill and back flow preventer shows a shut off valve on the supply side . When I installed my Caleffi auto fill and back flow preventer I decided to read the directions, they are so simple to install reading directions is a waste of time. The directions said to install a shut off valve on both sides of the auto fill and back flow valve so the valve can be serviced. I said that makes sense and followed the directions. I wonder why the back flow auto fill is not pictured like that in the Idronics journals.

I am thinking about running a hose from a water supply either to the boiler drain or else to the drain port on a isolation valve to fill the boiler to the correct pressure.

Do you have any ideas or thought on this. Or did I screw up somewhere.

hot_rod

Really no need for the second valve on the discharge side in my mind. Actually, there is a check valve built into the discharge of the auto-fill. If ever it needed service that could act as an isolation, it is a tight seal, spring check.

As far as isolation for servicing the back flow, the grey knob at the bottom of the Autofill is also a shut off, so you could isolate the BFD with just the valve on the inlet, and the shutoff built into the Autofill, 100%.

Send me a ship to address also. I was trying to contact you via PM but we don't seem to connect. bob.rohr@caleffi.com if you don't want to post you address here.

cutter

Hot Rod are you on Vacation. I was wondering what your thoughts were on the boiler fill.

hot_rod

the fill water will go up the bypass line and fill the boiler. The check should be to the right of the bypass tee as in the 6-14 schematic

cutter

hot rod said:

the fill water will go up the bypass line and fill the boiler. The check should be to the right of the bypass tee as in the 6-14 schematic

Hot Rod unless you are looking at a different printed version of Idronics #10 from what I have we are seeing two different things. The #10 I have shows the bypass on the boiler side of the check valve. That would make more sense though to put the bypass on the seperator side of the check.

siggy

I happened to come across cutter's post 192 regarding filling the pellet boiler with water (referencing figure 6-14 in idronics 10).

The Caleffi Monbloc anti-condensation component has an internal flapper type check valve that's intended to allow flow through the unit when the circulator is off. That flow would bypass the internal thermostatic valve element. The intent of this is to allow thermosiphon flow through the pellet boiler during a power outage. The check valve is held shut by the differential pressure created when the circulator in the Monobloc is operating. So, as long as the circulator is off there should be no problem filling the pellet boiler with water through its inlet pipe.

Hope that helps...

siggy

cutter

siggy said:

I happened to come across cutter's post 192 regarding filling the pellet boiler with water (referencing figure 6-14 in idronics 10).

The Caleffi Monbloc anti-condensation component has an internal flapper type check valve that's intended to allow flow through the unit when the circulator is off. That flow would bypass the internal thermostatic valve element. The intent of this is to allow thermosiphon flow through the pellet boiler during a power outage. The check valve is held shut by the differential pressure created when the circulator in the Monobloc is operating. So, as long as the circulator is off there should be no problem filling the pellet boiler with water through its inlet pipe.

Hope that helps...

siggy

Siggy, i am not filling the pellet Boiler, (actually I have a wood fired boiler that is not yet plumbed in) I am filling the conventional boiler and that boiler just calls for the thermostatic anti condensation valve. In the picture in Idronics 10 the bypass line is on the boiler side of the check valve. Not the other side as Hot Rod implies. To fix the problem I ran a 1/2" copper line from a tee at the boiler fill location (as pictured) to the by pass line. I put a valve in the line so it would only be used when filling that boiler. There is a little flaw in Caleffi's picture.

Thanks for the info though

hot_rod

cutter said:

siggy said:

I happened to come across cutter's post 192 regarding filling the pellet boiler with water (referencing figure 6-14 in idronics 10).

The Caleffi Monbloc anti-condensation component has an internal flapper type check valve that's intended to allow flow through the unit when the circulator is off. That flow would bypass the internal thermostatic valve element. The intent of this is to allow thermosiphon flow through the pellet boiler during a power outage. The check valve is held shut by the differential pressure created when the circulator in the Monobloc is operating. So, as long as the circulator is off there should be no problem filling the pellet boiler with water through its inlet pipe.

Hope that helps...

siggy

Siggy, i am not filling the pellet Boiler, (actually I have a wood fired boiler that is not yet plumbed in) I am filling the conventional boiler and that boiler just calls for the thermostatic anti condensation valve. In the picture in Idronics 10 the bypass line is on the boiler side of the check valve. Not the other side as Hot Rod implies. To fix the problem I ran a 1/2" copper line from a tee at the boiler fill location (as pictured) to the by pass line. I put a valve in the line so it would only be used when filling that boiler. There is a little flaw in Caleffi's picture.

IF you use the 281 ThermoBloc as shown in 6-14 it will fill, as the "gravity gate" aka check valve inside the ThermoBloc will open as you fill. It is a swing check and as long as the circulator is not running it will open.

If you use any other "protection valve" it may not allow the boiler to fill.

Either way the bypass line will solve the issue as you have discovered.

Thanks for the info though