Thanks so much for posting this content. Even in the worst case when we can't fix something (or break it more while investigating), we can learn from it - and maybe fix it next time!
We’re not allowed a rigid permanent connection in the uk, we use a filling loop which consists of a double check valve and two isolation valves with a braided hose between which you are supposed to disconnect when finished with-that rarely happens
Thank you for taking the time to add your insights and experiences! Do you in the UK use chemicals (i.e. anti-freeze, cleaners, rust inhibitors etc) in the boiler water?
Yes we do, because we have to use low water content condensing boilers inhibitors and magnetic filters on boiler returns are a must for warranty, heat exchangers are aluminium or stainless steel
Thank you for your reply! That all makes perfect sense. Here in the States, we have the world's largest heating museum complete with hands-on exhibits! With our functioning antique cast iron boilers for hot water heating, many do not see the need for chemicals at all. To say nothing of magnetic filters. So the worst that can happen is you will get nasty rusty tasting water in an unlikely back-flow situation. Many here add chemicals to their steam boilers, however. Accordingly, the Code enforcers here generally require an ASSE 1012 backflow which is sort of a poor man's RPZ backflow. For those that may not know, the RPZ backflow assembly is required if the water in the boiler could possibly make you un-alive.
On the last backflow video I tried to reply to your response about my use of an RPZ but as far as I can tell the comment did not post or at least doesn't show for me. I use the Caleffi 1/2 inch RPZ which is sku 574064A on supplyhouse. This is the propress one that costs less than the threaded one, but can be converted to the threaded one by removing the propress adapters. It cost about 80-90 bucks more than a standard backflow preventer. Given the choice I would always pick the RPZ whether residential or commercial. It's easy to justify by saying it will last a lot longer than the standard type for not all that much more money especially for a boiler replacement, or a customer that has gone through several backflow preventers. Caleffi also makes fill valve combos for hot water with an RPZ instead of a standard backflow. I have found that every single one of these dual check valve with vent types are just as unreliable. Whether it is the Zurn, Cash Acme, Watts, or Honeywell, they all seem to have issues. Where I am the water has a lot of scale and sediment. But it does not seem to affect the RPZs to the same degree. I've seen RPZs in commercial buildings that are 30 years old and still working perfectly, in the same towns where a standard residential backflow will last maybe 5 years at most. The Caleffi one in particular also comes with an air gap for the vent so it can be piped over to a drain. The fact that it comes with shutoff valves already on either side means you don't have to buy a separate shutoff valve. Once you include the standard backflow, shutoff valve, and fittings/pipe to go between them the price difference is even less. On a hot water system the Caleffi RPZ/fill valve combo gives you the backflow preventer, shutoff valves, and fill valve, already connected together and ready to install.
All of these ASSE 1012 units in general are problematic. Bladder-type expansion tank issues are mainly caused by poor installs and exacerbated by lack of maintenance, IMO. As far as fill valves go, I stick with the FB-38 and they seem to hold up a bit better than others.
Thanks so much for posting this content. Even in the worst case when we can't fix something (or break it more while investigating), we can learn from it - and maybe fix it next time!
We’re not allowed a rigid permanent connection in the uk, we use a filling loop which consists of a double check valve and two isolation valves with a braided hose between which you are supposed to disconnect when finished with-that rarely happens
Thank you for taking the time to add your insights and experiences!
Do you in the UK use chemicals (i.e. anti-freeze, cleaners, rust inhibitors etc) in the boiler water?
Yes we do, because we have to use low water content condensing boilers inhibitors and magnetic filters on boiler returns are a must for warranty, heat exchangers are aluminium or stainless steel
Thank you for your reply!
That all makes perfect sense.
Here in the States, we have the world's largest heating museum complete with hands-on exhibits!
With our functioning antique cast iron boilers for hot water heating, many do not see the need for chemicals at all.
To say nothing of magnetic filters.
So the worst that can happen is you will get nasty rusty tasting water in an unlikely back-flow situation.
Many here add chemicals to their steam boilers, however.
Accordingly, the Code enforcers here generally require an ASSE 1012 backflow which is sort of a poor man's RPZ backflow.
For those that may not know, the RPZ backflow assembly is required if the water in the boiler could possibly make you un-alive.
On the last backflow video I tried to reply to your response about my use of an RPZ but as far as I can tell the comment did not post or at least doesn't show for me. I use the Caleffi 1/2 inch RPZ which is sku 574064A on supplyhouse. This is the propress one that costs less than the threaded one, but can be converted to the threaded one by removing the propress adapters. It cost about 80-90 bucks more than a standard backflow preventer. Given the choice I would always pick the RPZ whether residential or commercial. It's easy to justify by saying it will last a lot longer than the standard type for not all that much more money especially for a boiler replacement, or a customer that has gone through several backflow preventers. Caleffi also makes fill valve combos for hot water with an RPZ instead of a standard backflow. I have found that every single one of these dual check valve with vent types are just as unreliable. Whether it is the Zurn, Cash Acme, Watts, or Honeywell, they all seem to have issues. Where I am the water has a lot of scale and sediment. But it does not seem to affect the RPZs to the same degree. I've seen RPZs in commercial buildings that are 30 years old and still working perfectly, in the same towns where a standard residential backflow will last maybe 5 years at most. The Caleffi one in particular also comes with an air gap for the vent so it can be piped over to a drain. The fact that it comes with shutoff valves already on either side means you don't have to buy a separate shutoff valve. Once you include the standard backflow, shutoff valve, and fittings/pipe to go between them the price difference is even less. On a hot water system the Caleffi RPZ/fill valve combo gives you the backflow preventer, shutoff valves, and fill valve, already connected together and ready to install.
Thank you for your insights and comments!
These devices are the most common thing to fail in my experience. Along with fill valves and expansion tanks.
All of these ASSE 1012 units in general are problematic.
Bladder-type expansion tank issues are mainly caused by poor installs and exacerbated by lack of maintenance, IMO.
As far as fill valves go, I stick with the FB-38 and they seem to hold up a bit better than others.