Ideal ICOS HE18 Please please please HELP!!!

[slw987]

Hi,

I am new to the forum and desperately need some serious help. I have an Ideal Icos HE18 boiler, installed in summer 2006. To date no probs, but now when the programmer is set to Auto/on/allday for CH settings and HW settings, the heating wont come on, but when hot water comes on the heating will then work until HW goes off.

There is no error codes on the boiler, it reads C when the HW is on but remains in standby mode (O) when the heating is on - hence no heating.

I have had an electrician test all the electrics, signals etc associated to the boiler/programmer/wireless thermostat as thought the command for heating not getting through - all ok.

I have a new Danfoss HSA3 Actuator fitted (3 way) as that was the initial problem (I was told) - still no heating.

Everyone is stumped to be honest as no sign of what the problem is - I have had 2 weeks of no heating now and am about to have my 4th engineer out to look at it.

Please if anyone could help, that would be great.

Steph

 

[Garfeild]

When the new actuator was fitted did they check the valve moved freely and was not siezed,cos it sounds a bit like it could be stuck.
Does the actuator head viewed when removed from valve,move accordingly when creating a HW/CH demand?

 

[Paul Barker]

I too think they should have changed the whole valve. They were lazy. All they have to do is shut any auto air vents drain a little water then with towel handy undo three nuts put new valve in tighten up.

 

[gas4you]

When the HW is on but the heating is off at the programmer, do the rads get hot?

If so this points to the valve body stuck slightly mid position and open.

If they don't then the valve is closed to heating whilst HW is on.

If the rads then get hot when HW and heating is on then the motor is moving the valve body but the microswitch in the head is failing to turn the heating on, or there is a wiring fault.

The HW is activated by the cylinder stat and the heating by the valve.

 

[slw987]

Hi again,

Ok, understand that prob might be the valve body and not the actuator. I have just turned the CH off and the HW on and no heating. However, when I manually push the rod on the actuator from left to right the heating comes on. When I then turn the hot water off and leave the heating on the rod does not move but the heating goes off. I am no expert and have just been looking into it all since no joy in getting it fixed and laymans terms are best

The actuator has been tested and works fine, infact the blinkin old one worked fine which dicovered when it was taken out - so problem obviously something else. I could get a new valve body fitted, but does is really sound like that as seems boiler only respond to HW command and if CH off when request HW no heat, if on when request HW works. Thanks for your help keep em coming.

Steph

 

[jackthom]

When you manually push the lever across, the valve ends up in the mid position and water can then flow from the boiler to both the CH radiators and DHW tank. Because you had the DHW ON in this case the boiler fired up, taking it's demand signal from the thermostat on the tank.

For CH only the valve has to move right across beyond this point to the CH only position. This time the boiler should get the signal to fire up from a microswitch in the valve actuator which is triggered when the valve reaches the far end of it's travel.

Assuming the actuator has been replaced and is OK, there's either an actuator wiring problem or the valve is sticking.

Do you feel up to checking the mains voltages on the valve wires with a multimeter or mains tester screwdriver?

 

[slw987]

Hi,

That sounds a bit scary lol working now till very late tonight, will be back online 1st thing tom, I have a maint tester scredriver (i think) depends how easy it is to do, would just need walking thru. Cheers.