weil mclain boiler & low hot tap water pressure


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Old 03-19-06, 04:56 PM
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weil mclain boiler & low hot tap water pressure

Can anyone tell me why we might have very low water pressure. It is a hot water on demand system. I did check through some of the forums, and see that psi should be about 15-18 for a two story house. The gauge on ours says about 10 psi. Why would this be and how can it be addressed. Also, we did put a new expansion tank (old one was leaking) on within the last year. I can't remember exactly when we put it on, but could the new one be failing and/or would it have anything to do with low tap pressure.

Thank you.
 
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Old 03-20-06, 06:58 AM
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Higher pressure isn't necessarily better. You want just enough pressure that the high parts of the system still have 4spi or so. If you live in a one storey slab house, 10psi isn't bad.

Has your system always been 10psi?

Have you noticed any water leaking from the pressure relief valve?

The thing I would be most concerned with to start is whether or not the system has any leaks. Do you have a valve looking something like this?

http://www.accentshopping.com/global...cts/911S12.jpg

If so, verify that any shutoff valves in line with it are open. if they weren't this may bring you up to 12spi and then you're good to go. Otherwise, lift the lever on the top until you see the pressure rise to about 15psi. Now close the shut off valve for the water feed and monitor the pressure to see if it drops (you are comparing cold temp pressures to cold temp pressures). If it drops, then you have a leak somewhere and you should find it and fix it.

If it doesn't drop over a day or two then try this. When the system isn't hot, open a boiler drain and let out some water until your system drops down to about 8psi then close the drain valve. Now open the auto feed valve. Without you lifting the lever, the pressure should rise back to 10 or more psi. If it doesn't, I'd get a new fill valve.
 
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Old 03-20-06, 10:28 AM
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Low Hot Tap Water Pressure

The pressure that is low is the water coming out of the hot water taps. I am curious if that has anything to do with the psi on the boiler. I will, however, share your reply with my husband. It might make more sense to him as he knows more about it anyways.

Thank you,

Gayle
 
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Old 03-20-06, 10:39 AM
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No problems...

Never mind my response, I was thinking that you were talking about your heating system.

You should post your message in the appropriate forum. Perhaps one of the moderators here will do so for you?
 
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Old 03-20-06, 02:33 PM
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Pretty sure it is the right forum

I'm pretty sure it is the right forum as we have a boiler that both heats the house and heats our hot water on demand.
 
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Old 03-20-06, 04:39 PM
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gditch

The boiler pressure & the lack of domestic hot water pressure are unrelated. I presume you have a tankless coil in the boiler from which you get the domestic hot water. If this presumption is correct, your coil is likely clogged. My experience with Weil McLain is not to try to clean the coil but replace it. I don't know what is different about Weil McLain coils but they just don't seem to hold up to cleaning.
 
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Old 03-20-06, 05:34 PM
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professional vs homeowner

As my original posting stated, my husband has replaced the expansion tank, can do the nozzle replacement, and has replaced a few other things on it himself. Is replacing the coils that you talk about something he can also do, or do you recommend that we have it professionally done. Is it a costly prospect?
 
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Old 03-21-06, 02:45 PM
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Coil Replacement

The one potential big bug-a-boo in replacing a coil is the possibility the bolts holding the coil in place will snap off. This is somewhat rare but it does happen. If it does, the remaining part of the bolt has to be drilled out & the threads re-tapped.
 
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Old 03-21-06, 03:58 PM
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Couldn't you use a screw extractor (I've never worked on boilers, just wondering from general principles)? That way, the threads should survive.
 
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Old 03-21-06, 04:23 PM
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screw extractor

Every time I've tried to use a screw extractor, the tool has snapped off & they are very hard steel.
 
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Old 03-21-06, 05:33 PM
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In other words don't ever sit across from Grady for an arm wrestling contest! L
 
 

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