Domestic hot water problem

Domestic hot water problem

PostBy: grassman On: Fri Dec 23, 2011 5:36 pm

I have a DF520 that works great except for the domestic hot water. The stoker is about 12 years old. When you turn the shower on the water is HOT but goes to luke warm in about 2 minutes. It was fine when we started the stoker in late Oct. but started this trick a few weeks ago. I'm not very happy with the tech. the dealer sends out so I'm hoping someone can help out. Thanks Matt
grassman
 
Stove/Furnace Make: EFM
Stove/Furnace Model: DF 520

Re: Domestic hot water problem

PostBy: k9 Bara On: Fri Dec 23, 2011 6:35 pm

Mixing valve failure maybe? :?:
k9 Bara
 
Stoker Coal Boiler: EFM
Coal Size/Type: Rice Anthricite

Re: Domestic hot water problem

PostBy: blrman07 On: Fri Dec 23, 2011 6:43 pm

coil scaled up?
blrman07
 
Hand Fed Coal Boiler: Bucket a Day
Hot Air Coal Stoker Furnace: Leisure Line Econo 1 stove
Coal Size/Type: Rice in the LL and anything that will fit in the Bucket a Day. It's not fussy.

Re: Domestic hot water problem

PostBy: Rob R. On: Fri Dec 23, 2011 6:54 pm

A mixing valve problem or scale buildup in the coil is possible, but let's start with the settings. What feed/air setting are you using and what are the aquqstat setttings?
Rob R.
 
Stoker Coal Boiler: EFM DF520
Coal Size/Type: Rice/buck
Other Heating: Dad's 1953 EFM Highboy

Re: Domestic hot water problem

PostBy: Mark (PA) On: Fri Dec 23, 2011 7:49 pm

Yes what boiler temps are you running?
Does your DHWC go into a holding tank or direct down the line to the sink or washroom area etc?
Do you use a mixing valve in your setup or no? (I don't on my setup)
When you started noticing issues with the temp was there any changes just before that to the system at all?
Mark (PA)
 
Stove/Furnace Make: 1953 EFM SF-520 High Boy
Stove/Furnace Model: Fitzgibbon Boiler

Re: Domestic hot water problem

PostBy: mozz On: Fri Dec 23, 2011 8:34 pm

Could also be a bad shower valve that is letting the cold get mixed into the hot.
mozz
 
Stoker Coal Boiler: Axeman Anderson 1982 AA-130 Steam

Re: Domestic hot water problem

PostBy: stoker-man On: Fri Dec 23, 2011 9:02 pm

It's not uncommon for a remote single-lever valve to cause this problem. Shut off the supply valves to every single-lever valve in the house, especially the washing machine and only let the shower valve on. If the shower returns to normal heat, open the others one by one, starting with the washing machine.
stoker-man
 
Hand Fed Coal Boiler: 1981 efm wcb-24 in use 365 days a year
Coal Size/Type: Anthracite/Chestnut
Other Heating: Hearthstone wood stove

Re: Domestic hot water problem

PostBy: grassman On: Fri Dec 23, 2011 11:11 pm

Yes there is a mixing valve for the domestic hot water, the original since the boiler was installed. There were no changes made to the system when this started. Now I will show my ignorance, I don't know what the settings are,feed/air or aquastat. The water temp. gauge is normally about 180-190 dgrees. Tonight everything worked good but will check all single lever faucets tomorrow. The thing that is odd , It doesn't do it all the time. Thanks Matt
grassman
 
Stove/Furnace Make: EFM
Stove/Furnace Model: DF 520

Re: Domestic hot water problem

PostBy: homecomfort On: Mon Dec 26, 2011 5:38 pm

the higher your boiler temperature, and the harder the water, the quicker the coil will become blocked and insulated with minerals, calcium. can be flushed out with muriatic acid, and will work like new.
homecomfort
 
Stove/Furnace Make: Franco-Belge,+ Penn Stove
Stove/Furnace Model: Normandie, + Chubby