What could be wrong with my heating?

[30ishflirtyandthriving]

We have an LPG gas boiler. We got back from holiday a couple of weeks ago and I noticed the radiators weren’t getting very hot so I had a mess with the dials on the boiler and that seemed to fix it.
We then had the boiler serviced on Monday and afterwards we were unable to get the heating to come back on.
The only way I have found to get it to come on is to put the htg/hw dial that is meant to be in the 12o’clock position anti-clockwise, which then makes the boiler kick in but makes the radiators be extremely hot and not able to be altered.
Could this be the diverter valve? Or the thermostat? I’m obviously no nesting engineer so all guess work but just wondered if anyone had faced a similar problem.

Have you got a room thermostat on the wall?

Is it a wireless one?

Post some photos of your boiler controls and thermostat.

We have a thermostat in the living room but it isn’t wireless.
It won’t let me post photos on my account for some reason I’ll try and find links for similar ones.

www.google.com/search?q=robus+thermostat&rlz=1CDGOYI_enGB651GB651&hl=en-GB&prmd=sivn&sxsrf=ACYBGNRbLssa8ip9lgFi1PsreplMXZL_xA:1572654882943&source=lnms&tbm=isch&sa=X&ved=2ahUKEwjQvJv9o8rlAhWRVBUIHWNwA-MQ_AUoAnoECA4QAg&biw=375&bih=547&dpr=2#imgrc=JieKx_92y7uZLM

www.freeboilermanuals.com/assets/pdf/ariston/euroCombiI.pdf

When you turn the wall stat up and down, does it click? At about what number? Does yours have the indicator lamp? On or off?

When you rotate it to the lowest number, do the radiators still keep heating?

The only way we can get the heating to turn on at all is to push in and turn the dial (on the manual I linked it’s on page 18, 3.3 diagram) They call it the selected for summer/winter/flue analysis mode? Would be a damn sight easier if I could post photos!
When we turn that clockwise, the heating then comes on full blast, and whether we have the thermostat at 0 or 30 degrees the radiators are still boiling hot. It clicks but only if you push the dial in and that’s at any number. It doesn’t click at any particular number. I don’t think it has an indicator lamp, it has a little bulb which isn’t lit up but I can’t remember if it ever is!

The dial I mentioned that makes the heating come on is on the boiler by the way not the thermostat. It’s meant to be at the 12oclock position but when it is we have no heating at all.

Just ask the person who serviced it to come back and fix it.

If you are using the knob marked "flue analysis" I think that will be the test setting that puts the burners full on, overriding the normal controls.

When you say you had a mess with the controls you may have set something wrong, but I don't know what.

Have a look at the CH timer/programmer to ensure it is set on. If that, and the wall stat are both calling for heat, and the boiler does not fire, but it heats the hot tap water and runs on Flue Analysis, it may be an electrical fault around the controls, possibly around the timer or wall stat. you need your mender back.

@PigletJohn That would make sense, we must be putting it on that test setting when it comes on. I only messed with the dials and not the controls ie timer or anything like that but I’ll have a look and double check the settings. Hot water is fine we’ve had no issue with that at all.
Do you think it could be the thermostat?
Thank you for all your advice you have been a big help.

might be

but the type in your pic is (probably) very simple and reliable. There are a few looking like that with electronics inside, but most of them are a simple thermostatic switch and are still working when they're replaced by new after 30 years or so. not much inside to go wrong, and no particular reason for the wiring to go wrong.

@PigletJohn I am now able to post photos! This is the boiler and I’ll get one of the thermostat

This is it

Thermostat

in the pic, the thermostat seems to be turned to "very cold" so the heating would be turned off. Turn it to 30.

Where's your timer?

second knob looks like it is turned to the tap. i.e. hot water only, no radiators. Turn it so it is pointing straight up. I can't see what the third setting is.

@Pigletjohn we’ve had it on all temperatures and it’s not made a difference, so when the radiators were full blast we just turned it to as low as we can and it still didn’t change so we’ve just left it.
We’ve had it pointing straight up (that’s how the people that serviced it left it) and then the rads don’t come on at all whether stat is at 0 or 30.
I think the timer is on the boiler itself? We’ve never worked it out since we moved in! Just used the thermostat to turn heating on and off.

try a close up photo of the timer, bottom left of the boiler panel.

Turn up the wall stat.

And please turn the leftmost on the three knobs to point upward.

We had a problem with our boiler. Managed to find the switch which turns it off then we put it back on again and it 'fixed' itself.

@PigletJohn I’m on it!

@PixieDustt we’ve turned it off at what I assumed was the main fuse for it but I no idea if it was the right one!

Still nothing

@PigletJohn oh hang on.. done as you said and it feels like they’re coming on!!!

I’ll leave the stat at 30 for a while and then I’ll lower it and see if they get cooler! Thank you so much