problem with regular y-plan system...

[Aqua Tech]

hi got a problem that is baffling me.

we put in a new regular boiler onto a y plan which has an old switchmaster set up. All seemed to go fine apart from a call three months later. When the heating and hot water are put on together the hot water becomes scalding?

Checked to see if it was 3 port valve but that seems to work fine, then tried a new cylinder stat and seem to still get the same problem...

THe only thing that has really changed is the wiring was moved around a slight bit because of the permenant pump live that was needed with the new boiler. Could this be the problem?

any ideas are welcomed...

 

[fuzzy]

wiring issue i presume, the 3 port allowing primary water to cylinder even when satisfied. check 3 port wiring, or could work properyly but the 3 port is passing, what type of 3 port, how old?

 

[quality]

When you say you checked the 3 port what did you check as it could appear to operate but as fuzzy stated it could be passing

 

[Aqua Tech]

its a very old system master, that takes ages to click around...

 

[Aqua Tech]

i checked that when on heating only the pipes are not getting hot to the coil...