IDEAL ISAR HE35 BOILER-HEAT BUT NO HOT WATER-HELP REQUIRED!

[stevie-h]

Perfect Xmas timing! Need help with an Ideal Isar HE35, giving heat but no hot water. No fault codes showing on the display, seems normal- tried switching off and on, shutting off heating etc.- nothing. Pressure is 3.0 on gauge with heating on. DHW thermistor, Diverter valve, Control thermistor? Any help or guidance appreciated... Merry Xmas!

 

[gas4you]

Firstly pressure should be about 1.2 cold, rising to about 2 hot.

When you turn the hot tap on does the boiler show 'd'?

Does it try to fire?

Or does it fire up showing 'd' but no hot water is produced?

 

[Agile]

One wonders why the pressure is too high? But it would not stop it working.

If the boiler indicates a demand for hot water then the diverter valve is probably stuck. Usually indicates some dirt in the system.

They can usually be manually operated to free them up for a while. But it usually sticks again later.

Tony

 

[stevie-h]

Thanks for that - when the hot tap is on the boiler shows 'D', seems to fire up but no hot water. I'll take a look at the diverter valve.

 

[gas4you]

Although Ideal insist that they can be cleaned out, I, as yet , have never had one that works after cleaning, so I just replace as standard now.

 

[stevie-h]

'D' on boiler is now lit constantly ('dripping tap' but everything is off) burner light is flashing constantly, drained some water off, pressure is now 2.5 bar...

 

[gas4you]

Turn off cold inlet valve under the boiler. Only way you can be sure there is no drip or leaks anywhere to hold it on 'd'.

 

[stevie-h]

OK, the 'D' is off the display and I've removed the Wilco diverter valve control box, do you know how to manually over ride the valve? Thanks...

 

[gas4you]

Valve should always rest in dhw position.

Is this one of those red box type valve heads that they used for a while. Still Honeywell though I think.

 

[stevie-h]

Not red but it's a honeywell, VC6012-34 on the white label with red border. Freed the valve off which was pretty stiff, not giving hot water in either position though. Doesn't seem to be firing either. 'C' on display with burner light lit. Pressure seems fine, all connections good. Totally lost now...

 

[gas4you]

Have you turned the cold inlet valve back on?

Isolate ch flow and return, keep head off. drain boiler via boiler drain offs.

Remove metal crossbar support.

DV body is removed by undoing the 4 large allen key bolts that will face you. From under the boiler there is a phillips head screw that holds the dv in position if I remember correctly.

This is all clearly explained in your MI's.

Do you really want to be trying this on xmas eve with no new parts to fit

I wouldn't

 

[stevie-h]

SORTED! Did what you said, worked the valve a few more times and it's kicked in. Think there was some crud in the workings and it'd siezed. I'll have to run with it manually for a coupla days until I can get a new valve and actuator but it'll be fine till then.
What can I say - THANKS !!! I was drinking in the 'Last Chance Saloon' on that one, for sure.
Much appreciated, all the best to you and yours for Xmas and New Year, (I'm off for a shower... )
Stevie.

 

[gas4you]

See if you can order just the valve assembly without the head. It is usually this that causes the problems.

 

[stevie-h]

-just managed to pick one up off eBay, £35 new - dealer price £100+!
Thanks again...