Baxi Combi 105 HE ch variable

[mscarlyon]

I've just moved into a newly refurbished property with a Baxi Combi HE boiler. Everything seemed fine until I wanted to use the central heating earlier this week. As recommended in the operating instructions I put the selector to hw/ch and the timer on constant, but this didn't work. I tried it using the timer, and it still didn't work. I turned the temperature control to maximum - it still didn't work. However, I know the system's working as the central heating decides to come on randomly whenever it feels like it. But so far not when I want it to As far as I see there is no room thermostat anywhere in the property that might be affecting it. Please can anyone help? Thanks

 

[Agile]

I assume the rads heat up when it comes on unexpectedly?

If so then one can assume its a boiler problem.

It might be that the DHW demand switch is stuck on but what ever it is I dont see that you are going to be able to do anything about it!

Does the boiler come with any kind of installers guaranty?

Tony

 

[mscarlyon]

Hi Tony

Yes the rads heat up no problem - when the heating decides to come on! I've been having a good look for an installers gurantee, but before pursuing that route I thought it might just be something very simple I'm not doing right! The operating instructions are very basic and don't include any kind of troubleshooting guide.

When I moved in the owner showed me how to use the system and it was working fine then...

Thanks for your help, anyway

Caroline

 

[gas4you]

What sort of timer is it. Built in? Digital? Mechanical dial?

 

[mscarlyon]

The timer is a mechanical dial. There are only three settings for it - Off, Timer and Constant.

Caroline

 

[gas4you]

Where are the click in tabs positioned around the dial?

 

[mscarlyon]

At present the click in tabs are all off. The setting on the timer is on 'constant', the selector is on both hw/ch which means the heating should be on now! I've tried setting the timer for it but it made no difference. What I don't get is why it comes on at some times and not others when there is nothing to tell it to do so.

Caroline

 

[mscarlyon]

I mean the click-in tabs are set to be 'on' rather than 'off', regardless what time it is.

 

[mscarlyon]

Can nobody out there amongst all you boiler experts come up with any possible reason why I'm getting this problem?

 

[ChrisR]

I have found several dodgy timers on those. Eg sometimes they come on in "timed", "on" position but not the "1" position. It sounds like you may have that covered, but perhaps it's worth another look. Try wiggling the 3 position switch on the timer.

Does the hot water always come on ok?

Can nobody out there amongst all you boiler experts come up with any possible reason why I'm getting this problem?

That comes across as a bit unreasonable, You have an intermittent fault. It could be any of a dozen places.

 

[Agile]

There are several faults which could cause that. As it seems that you are doing the right things with the user controls perhaps there is a fault

Now that you have mentioned an "Owner" I am left wondering if you are a tenant in which case ask the Landlord.

If you have bought it then it does sound as if there is a fault and that will require a competent person to identify the problem.

Tony

 

[gas4you]

Also sounds as if it will still be under warranty

 

[Flow Switch]

The boiler may have a DHW pre heat so the boiler maybe trying to go to top up all the time i have had this fault quite a few times and can be down to sludge in the diverter sections ? hard to diagnose without being there