EFM DT 520 PSI

Becker · Post by **Becker** » Wed. Mar. 10, 2021 4:07 pm

My EFM DT 520 is pushing my psi up to 35, causing the pressure release valve to go off. My pressure release valve is rated for 30 psi. Any ideas where to begin fixing this situation?
Thanks.

nepacoal · Post by **nepacoal** » Wed. Mar. 10, 2021 4:17 pm

The most common issue would be the expansion tank failing... Do you have a bladder tank or big steel tank? Bladder tank would need to be replaced, steel can be drained to correct psi.

If not that, your DHW coil may be leaking inside boiler.

Holdencoal · Post by **Holdencoal** » Wed. Mar. 10, 2021 4:35 pm

The expansion tank is dead or lost pressure. You will have to unpressurize the system and measure the tank pressure. If it’s not reading correctly, replace the tank and pressure relief.

Becker · Post by **Becker** » Wed. Mar. 10, 2021 4:43 pm

My pressure tank is a big, old steel, tank mounted to the ceiling. I could only get water to flow from it by leaving the boiler fill valve open, which pushed cold water through the tank. Any ideas?

nepacoal · Post by **nepacoal** » Wed. Mar. 10, 2021 4:58 pm

You may have a special "drain o tank" type valve already installed. Without something like this it can tank a long time to drain the tank. Check to see if you have one... You need to isolate the tank by closing a valve on the pipe that feeds the tank. Then drain the tank completely out of the valve at the other end.. then just close the drain valve and reopen valve on pipe feeding the tank. It will fill about 1/3 with water and leave 2/3 air for expansion. Will need to be done every couple of years...

nepacoal · Post by **nepacoal** » Wed. Mar. 10, 2021 5:03 pm

Here's a video of an Internet plumber draining one with a different type of "special" tank valve...

Post by **coaledsweat** » Wed. Mar. 10, 2021 5:21 pm

Could be the WATTS or similar feed valve, no?

nepacoal · Post by **nepacoal** » Wed. Mar. 10, 2021 5:42 pm

coaledsweat wrote: ↑
Wed. Mar. 10, 2021 5:21 pm
Could be the WATTS or similar feed valve, no?

It's a remote possibility, but those feeder valves usually get stuck closed...

Post by **coaledsweat** » Wed. Mar. 10, 2021 5:49 pm

Easy enough to troubleshoot. Shut the feed off and if it stops going up, its the pressure reducing valve.

pintoplumber · Post by **pintoplumber** » Wed. Mar. 10, 2021 5:52 pm

coaledsweat wrote: ↑
Wed. Mar. 10, 2021 5:49 pm
Easy enough to troubleshoot. Shut the feed off and if it stops going up, its the pressure reducing valve.

Unless it’s a pinhole in the coil.

nepacoal · Post by **nepacoal** » Wed. Mar. 10, 2021 6:00 pm

The OP joined in 2018... If the tank hasn't been drained since before 2018, it's likely the expansion tank needs to be drained... Mine usually needs it every 4 or 5 years. I drain it when it starts getting up past 20 psi.

Becker · Post by **Becker** » Wed. Mar. 10, 2021 6:20 pm

Thanks everyone. I got it drained. It must have been full. If not, I'm thinking about replacing the fill valve. It's rated for 15psi. It may be shot. I'll tick off one suspect at a time before I tear into the DHW coil.

nepacoal · Post by **nepacoal** » Wed. Mar. 10, 2021 6:27 pm

What's your psi after draining the tank?

Holdencoal · Post by **Holdencoal** » Wed. Mar. 10, 2021 6:41 pm

nepacoal wrote: ↑
Wed. Mar. 10, 2021 5:03 pm
Here's a video of an Internet plumber draining one with a different type of "special" tank valve...

Steve isn’t just any oh internet plumber. He’s the real deal.

nepacoal · Post by **nepacoal** » Wed. Mar. 10, 2021 6:43 pm

Holdencoal wrote: ↑
Wed. Mar. 10, 2021 6:41 pm
Steve isn’t just any oh internet plumber. He’s the real deal.

Yeah, I watch all his boiler videos... Educational and entertaining!

EFM DT 520 PSI

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