amtrol boilermate output pressure

onyaw

Dear all,

We have an Amtrol BoilerMate 41 gallon indirect water heater in our home (here when we moved in). I know many aren't fans of this brand but we familiar with these from our old home and it heats well enough. While the heating is okay i've noticed that the hot water pressure on all taps is lower than the cold, including the showers - want more hot water pressure there. Shower cartridges and filters are all clean. We have a well and a constant pressure well pump, and frequent lime or calcium scaling on our taps, etc. So I wonder if there is significant scaling where the water comes out of the Amtrol, restricting the output. I read somewhere that removing the output connection from the top and scraping off the scaling can restore the pressure but have only seen that once and don't recall if it was an Amtrol or another brand. On our unit I notice that there are wrench marks on the nut, suggesting that this has been done before.

Is this a big job for a handy homeowner without calling in a pro? I wonder if i just turn off the well pump, run out the hot water through the taps, whether i can just unscrew the nut at the output pipe and figure out how to clean it and put it back. i.e. without draining the tank, etc.

Is it that easy, or more to it? Without the well pump on, and with the taps open, there won't be pressure - right? Is there a gasket in there that I would need to be ready to replace? Also, is it okay to just leave the thermostat wired while I'm doing the work?

Thanks,

Zman

What type of piping is in the house?

onyaw

copper

onyaw

i thought maybe it was just pipe expansion when hot or warm, but i tried it after the boilermate had run down/boiler hadn't caught up yet, or when there were cold pipes. the pressure was still lower (although i've not measured it yet).

HomerJSmith

What is the standing water temp in the indirect tank? A mixing valve on the output?

Well water is always suspect.

onyaw

standing water temp is 127 oF. i guarantee there is deposit on the coils but they are bottom coils so i am not about to do that. i'm guessing the unit is about 10-12 yrs old. i don't see a mixing valve at the top, just a standard relief valve. at least one of the pipes goes up to the ceiling without any stops. i think the only mixing after that occurs at the taps or thermostatic cartridges.

Jamie Hall

You are basically on the right track with the scaling Somewhere in the system there is a flow restriction which isn't present on the cold water side.

It's unlikely to be in the tank itself -- that has almost no flow restriction at all -- but it could be the outlet. However, before I started taking things apart I would look through the whole system. Start where the pipe for hot water comes off the cold water main, and compare for each -- what valves are there? Pipe sizes? Any strainers or filters? Trace it right through to at least two or three different points of use. Keeping in mind that even one significant restriction present on the hot water side which isn't on the cold water side can cause a significant difference in the resistance, and thus a difference in flow for the same pressure -- or pressure for the same flow -- at the point of use. Globe valves are particularly suspect this way, even if they are "fully" open.

EBEBRATT-Ed

IT could be in the Amtrol but more likely in the faucets.

I would remove the hw pipe and clean that connection then install a tee with a boiler drain near by on the hot water line, That will give you a place to check the hot water outlet pressure

Larry Weingarten

Hi, I agree with @EBEBRATT-Ed , Measuring water pressure at different points while water is flowing will help you to pinpoint where a restriction is. Try measuring with one faucet running, then two. I like to measure pressure at the line coming into the house (both static and under flow) to see if there is a main line restriction. Measuring before and after the tank is useful. hooking up your gauge to the shower arm is a good place to measure while running other taps. You can find adapters to screw into faucets where aerators live and measure pressure there. With all this data, you'll know where the restriction is and isn't. From there, you can see what really needs fixing.

Yours, Larry

rick in Alaska

Personally I would put a bucket under the relief valve and see how it is doing there. If it does have good pressure there, then the problem is in the house piping. If you don't get good flow there, then something is restricting the water through the tank, and I would be more inclined to say the water coming in to the tank has a restriction.
If there is a drain valve at the bottom of the tank just past the shutoff valve, then you can open it up and see how it is flowing there, and if it does have good flow, then you know the restriction would be in the tank. If not, then it has to be the shutoff valve or something before that, in which case you would need to track the cold line back to the main line and see if there are any other valves in the line, and take them apart to check them, if needed.
Rick

onyaw

Thanks everyone, these are all great suggestions. I will have a careful think about what to look at first and begin testing.

onyaw

I began testing with a handy-dandy $10 pressure gauge i just bought, and both the outside faucet (cold only) as well as the drain from the bottom of the Amtrol are at 60 PSI.

I then had to get an adaptor from 3/4" female (gauge) to 1/2 " male to check faucets. The adaptor nipple is too shallow to thread into the sink faucets but i put them on the sprayers on all three of our showers. Our two 'secondary' showers both show about 60 PSI for hot and cold. But our 'main' shower shows about 5-10 PSI units lower for hot. This 'feels' about right for the difference we are missing. We not so long ago had pros in to help clean out crap from the filters on our (fancy Italian) main shower hot and cold sides. And a brand new cartridge. I suppose that more crap came into the hot side filter and that I should go in there to clean it out. Good news, I won't be messing with the Amtrol.

Thanks again for encouragement and suggestions.

onyaw

I meant 'check valve' not 'filter.' its this unit (see attached pic) that isn't doing the pressure right, in case anyone has suggestions other than to clean out the check valves again. the cartridge itself is only 1 yr old.

Zman

There are screens inside that valve. Have you checked to see if they are plugged?