overtemp fault on ravenheat LS80T

[druid]

Hope someone can help?
I'v got the overheat light lit on the boiler
power on
water pump starts
no fan(no power to fan)
no power to overheat thermostat?

could someone tell me is the overheat thermostat N/C switch or is it a sensor? or am I barking up the wrong tree?

Many thanks simon

 

[gasmick2]

hi have you tried to manually reset the overheat on the front panel there is a screw cap that can be removed and a reset button behind it
But if its gone into overheat condition there is a reason perhaps the pump or the heat exch getting clogged up

 

[druid]

Thanks for the reply.
there is no manual reset tho O/T STAT it is ment to auto reset? and is testing as closed with a meter.

Any help or test info would be great.

Many thanks simon

ravenheat LS 80 T white star

 

[gasmick2]

hi simon can you give me the GC number for the boiler i have looked at all the info i have and on the LS 80t the gc number is 474 81 29 can you confirm which one it is
as these do show a manual reset for the overheat on the front panel as with the other models
And the overheat stat is a switching device set at a max of 95 degs that protects the heat exch should the normal boiler stat go which should be set to max 85 deg via a thermistor

 

[druid]

thank you the GC number is 47 581 30

Many thanks simon

 

[gasmick2]

ok simon i have just found the relevent service book for the model on my boiler cd and it states on page 7 an overheat cut off stat set slightly higher than the high limit stat and acts to turn off the burner to a "RESETABLE LOCKOUT" fig 50 item 3 on page 28

please can you look to see if the maunual is the same as you have got

 

[druid]

Page 7 is as you stated but page 28-fig.50 has no item 3?
1=mains switch/reset
1A= summer/winter switch
4 = ch thermostat
5 = dhw thermostat
green power light
red flame-overheat light
timeclock
7=pressure gauge ch

could you let me know where item 3 connects on the board?

Many thanks simon

 

[gasmick2]

hi simon a bit of further information there is 2 models a mk1 and a mk 2 you must have the mark2 model which as you say has a auto reset overheat and if the red light is flashing then its in overheat mode but if its just lit and stable then its down to flame failure so first try turning it off at the wall socket for 2 mins and then back on again and see if it resets everything
if its a different kettle of fish and it could be a number of things you will need a corgi engineer to check out the gas valve and the rectification
and poss the A P S

best of luck

 

[druid]

Many thanks

As the fan is not starting i dont think it would get as far as a flame fail?
so I'm thinking
dhw thyrister checked ok
ch thyrister checked ok
pump running ok
dhw flow switch working ok
low water pressure switch ok
and
over heat stat closed but no power to it it must by a pcb fault?

would this make sense

tested air flow switch ok
No power going to fan?

Many thanks simon

 

[gasmick2]

hi Simon well it does sound like the p c b it could be the control pcb
the only problem is that you should not replace it yourself because the gas regulation will need to be set to suit the demand of your system load and that can only be carried out by an R G I
Most Ravenheat boilers leave the factory set at 55,000 btus on the heating side

 

[druid]

Many thanks got new pcb fitted all up and running fine
Think I'll look at putting in a wood burner with backboiler next year?

simon

 

[gasmick2]

great glad you got it sorted

mick