Watts Pressure Relief Valve Replacement


  #1  
Old 04-04-15, 08:29 AM
J
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Watts Pressure Relief Valve Replacement

Well spring has finally arrive in the NE, and not to soon.

Originally, the backflow protector was leaking. But after getting a replacement, the slow leak has stopped. Yes, nothing for the last few months.

However, now the pressure regulator is leaking, and getting worse - ~30 oz of water/day.

Looking at the attached picture, this looks fairly straightforward:

- Turn off water coming into the system with the valve to the left of the backflow preventer.
- Turn off the return valve on the left side of the boiler,
- Turn off the supply valve either above or below the circulator pump on the right side of the boiler,
- Drain some water from the spigot on the bottom right of the boiler to both releave the pressure, and drop the water level below the relief valve height.
- Replace the valve
- Open the 3 valves and refill the boiler with water
- Do whatever purging is necessary.

A few questions:

1. Have i got it right?

2. How much water should I initially drain prior to changing the valve?

3. When I open the return and supply valves, I expect water from the 2 zones is going to flow into the boiler and I'll have to purge these zones. Any way around this?

4. What would cause the backflow preventer to stop leaking? I've thought about replacing it at the same time, but 3 months of no leak, then why tinker with it?

Thanks
 
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  #2  
Old 04-04-15, 08:58 AM
G
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What is the system pressure and temp as indicated on the boiler gauge?
 
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Old 04-06-15, 11:06 AM
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Pressure is 23 PSI.

Temperature is in normal range 160 - 180 as system cycles.

Both normal
 
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Old 04-07-15, 11:40 AM
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bump

Any feedback?

thanks
 
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Old 04-07-15, 12:30 PM
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Yes your process is correct. Possibly there will not be much air and the air elimination device will remove without a purge..

But your expansion tank or fill valve can be the cause of your leaky prv..

Additionally your gauge may be off and your are at or near the 30 psi rating of the PRV..
 
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Old 04-08-15, 08:13 AM
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But your expansion tank or fill valve can be the cause of your leaky prv..
Thanks. I'd like to test these first before replacing the PRV. I seem to recall a thread on testing the expansion tank; I'll search for it.

1. Is there any way to test the fill valve? The backflow preventor did have a leak, but it stopped. How would a bad fill valve effect the PRV?

2. And, is there any way to test the pressure gauge?

3. Also, does the fact that the amount of drip is increasing (now easily 30 oz/day) eliminate certain parts, e.g. the pressure gauge?

Thanks
 
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Old 04-08-15, 08:42 AM
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Read the stickys here. PRV leaking and pressure gauge area.. Then post back any questions..

Boilers - Home Heating Steam and Hot Water Systems - DoItYourself.com Community Forums
 
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Old 04-09-15, 04:12 AM
J
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Thanks. I followed the sticky procedure for testing the expansion tank last summer when some other work was being done on the system; I'll do it again now. I'll also verify the pressure gauge as per the sticky.

But your ... fill valve can be the cause of your leaky prv..
1. You also mentioned it could be the fill valve. How would a bad fill valve effect the PRV? And how can I test it?

2. I've also noticed the pressure readings on the system appear to have dropped. When I responded earlier to the thread, PSI was 22-23. Now it is ~18 PSI when the boiler is not running, and ~16 PSI when it is running. Is this still in the normal PSI range, or an indication of some other problem?

Update - after cycling for the last hour, PSI is at 20.

3. The backflow preventor had a leak, but it stopped completely 3 months ago. While I have the replacement, I'm tempted to follow 'if it an't broken, don't fix it'. Any thoughts given what else i might need to do on the boiler?

You can see from my questions that I not only want to fix the boiler problem(s), but also understand the system better.

I much appreciate the feedback.

Thanks!
 

Last edited by jdbs3; 04-09-15 at 04:51 AM.
 

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