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snapfitme70 · Apr 21, 2009, 04:38 PM

I have little hot water pressure. The cold is fine, comes out with excellent pressure. I was reading that I have to drain the hot water boiler to get rid of debris that might be in there. I have a weil-mclain p-468-wt. is this something that and amateur could handle or should at this point call someone?

ballengerb1 · Apr 23, 2009, 04:27 PM

So this is an actual boiler and not just a hot water heater, right?

snapfitme70 · Apr 23, 2009, 04:31 PM

Yes that is correct. I do not have a waterheater.. the boiler (furnace) heats my hot water.

ballengerb1 · Apr 23, 2009, 04:32 PM

That's going to be out of my league but I'll see if Speedball1 or Mark can jump in.

massplumber2008 · Apr 23, 2009, 04:38 PM

Hi Snap...

Bob asked me to pop in and see what I could think of...

Are we dealing with a TANKLESS COIL in the boiler or a separate zone valve with a storage tank off the boiler? Also, was pressure ever very good? Is this new issue or old issue? Back to you...

MARK

snapfitme70 · Apr 23, 2009, 04:59 PM

It is a coil system that is one side to the boiler.. the other side is the heating for my baseboard heating system

snapfitme70 · Apr 23, 2009, 05:00 PM

It just happened.. few months now.. just thought it would stop.. but it doesn't seem to be fixing itself

massplumber2008 · Apr 23, 2009, 07:22 PM

Hey hey!

I have seen the results of a tankless coil that is plugged on the inside, on the outside (clogging fins of the coil so heat transfer is poor), and on the inside and outside. Your system may be clogged on the inside... reducing the VOLUME of water available for heating and presenting as a loss of pressure to you.

First, I wonder if there is a boiler drain (see picture) associated with the tankless coil? It would be great if you could confirm/compare volume of water INTO tankless coil and/or directly OUT of the coil.

If not, next thing would be to check the shutoffs feeding the cold water into the coil and then check any shutoffs on the hot water line after the coil. You may even need to check the MIXING VALVE to be sure that this is an issue with the coil itself and not just an issue with a valve/shutoff... O.K.

If this is a shutoff/valve... that's great! If not, then you may want to consult a pro. And discuss options to clean the coil itself. Options include citric acid solution (or similar) being pumped through the coil to dissolve hard mineral deposits, ultrasonic cleaning of coil (see link:"Ultrasonic" cleaning of Tankless Hot water coil. ) or a few other methods up to and including replacement of the coil.

Let me know what you think...

MARK