When my boiler turns on to heat house I lose hot water? why?

Joe.G

Why do I lose the hot water in the house when my boiler turns on to heat my house? The boiler can turn on to heat the hot water and I don't lose it only if it kicks on to heat the house? thanks
P.S I don't have a seprate hot water tank it is built in to my boiler.

Doug Wagoner

Boiler water temperature drops

from the returning cold water in the heating system. This is the same water surrounding the tankless coil furnishing you hot water to your faucets. Is your heating system base board?

Steamhead

Sounds like

cold water returning from the system is hitting the tankless coil and chilling it. This may be due to improper piping connections. Try looking on the Find a Contractor page of this site for someone near you who can straighten this out.

To Learn More About This Contractor, Click Here to Visit Their Ad in "Find A Contractor"

Joe.G

I have old cast iron raditors, It is not that big of a deal since I just make sure the heat does not come on while i am in the shower. It does not seem to be as bad if the heat has been running for a little while.

[Deleted User]

sounds like

there is no bypass pipe between the supply and return, as needed with high water content systems. This protects against thermal shock, as well as giving your triple aquastat time to notice the change in temperature and stop the circulator before the coil gets chilled.

Noel

J.C.A.

I agree with Noel, but.....

Did the control to protect the boiler from heating when the temp. is too low get set wrong (or not installed at all) ?

Use the "Find a Contractor " link at left and have a pro look at it . Chris

jg2700

yeah when your heat kicks on all your btus are going through the heating loop . how old is the boiler has it been serviced.what size boiler and what are you fireing it at. could be many things to consider here.

Joe.G

The sytem gets serviced at least once a year most of the time twice a year, the boiler is from 1947, the motor is a becket and the boiler works great, use a little more fuel then I want but it works well.