Ideal FF350 intermittently not firing up

[gwynant]

I have a s-plan heating system with an unvented cylinder, and a fairly old (20 year old) boiler.

Recently I've noticed that sometimes when the thermostat calls for heat, the boiler will not fire up. The usual click will be heard, and the pump will start running, but no more than that. After a while the pump will stop running, and then this cycle will repeat again until I turn down the thermostat.

There are times when the boiler will operate as normal, and fire up for 1+ hours in the morning to heat the house and the hot water. However if gets colder during the day, the above cycle will often happen.

I've:

• bled all the radiators (there wasn't any air anyway)
• checked the pressure of the system (normal, as it always has been)
• had a plumber out (typically it worked fine during his visit so 'no fault found')

I'm not averse to getting a new boiler, but as the plumber said that it's working well, I'd rather not go straight down that option!

Do you have any ideas of what the issue could be, and how to resolve it?

 

[ianmcd]

Oh a 20 year old boiler, well that narrows it down

 

[CBW]

Check the wiring center for a loose connection, and the motorised valve. As per @ianmcd, we can’t advise on the boiler we know nothing about.

 

[gwynant]

Thanks for your responses both.

The boiler is an Ideal FF350.

Both motorised valves are opening and closing without issue, and as far as I can see there are no loose wires.

It can be working fine one part of the day and then playing up later on - that's how intermittent it can be, and how frustrating the issue is to figure out...!

 

[ianmcd]

decent boilers and worth keeping going, there is a common part on these that causes your problem, but it is gas related so cant be discussed on here due to site rules, get somone who knows this boiler well to properly service it, not just a poke and go cowboy

 

[DP]

decent boilers and worth keeping going, there is a common part on these that causes your problem, but it is gas related so cant be discussed on here due to site rules, get somone who knows this boiler well to properly service it, not just a poke and go cowboy

Where are the 'professional' advisers? Question too difficult for them?

 

[bernardgreen]

there is a common part on these that causes your problem, but it is gas related so cant be discussed on here due to site rules,

It might help to mention what part might be the cause. Then the OP has the knowledge to better evaluate if the repair man knows what he is doing or just is changing part after part until he gets lucky and changes the faulty part.

 

[ianmcd]

It might help to mention what part might be the cause. Then the OP has the knowledge to better evaluate if the repair man knows what he is doing or just is changing part after part until he gets lucky and changes the faulty part.

no because someone else will see the post reckon they have the same problem, will order the part on tinternet and fit it without knowing what to do

 

[gwynant]

Hi all, just to give an update - another gas engineer came twice over the last 2 days to have a look. The first time the boiler happened to work fine, the second time the boiler wasn't responding, but as he cover was taken off, it sprung to life, before switching off again a few minutes later.

The voltage detector he used found no power to the fan (all other components had power reaching them I think), but as he wasn't also an electrician now I need to get someone else out - which I'm really struggling with at the moment as none of the multi-trade companies I'm aware of are even responding!

Does the likely issue need an boiler-electrician out or would a regular electrician suffice? I'm guessing it's some faulty wiring(??) but I know you may not be allowed to advise on that.

The boiler is working as normal again now but I know it's going to break down again in a few hours... oh the joys of trying to resolve an intermittent issue!

 

[CBW]

I’ve never heard of a boiler electrician, you need a gas safe registered engineer who’s competent with electrics and preferably someone familiar with that type of boiler.

 

[ianmcd]

No you need a decent boiler engineer not a guessing clown and definately not an electrician , just get Ideal out to it instead of using clueless idiots