Vaillant Eco Boiler - Heating will keep coming on and off at random times!

[steveb21]

Radiators keep coming on and off, could just be a coincedence but I have noticed this happens on really cold days/nights. Frost protection?
I have the Hot Water and Radiotor dial on the boiler turned to half way.
Thermostat in house switched off or set to under the dispayed temp.

On the odd occasion the boiler would:
Give error F24 - low pressure (which i beleive could be a number of things). This usually happens over night when the heating has been off for a longer than usual period of time.
Let out some black type fluid in around the boiler area (This normally happens when F24 code pops up)
I have also noticed that a few of the radiators downstairs do not heat up fully, always appear to be cold from bottom and hot-ish at top. This has been the issue since the new radiators were installed.

Info on recent changes.
Dormer Bungalow with:
8 new radiators downstairs
5 new radiators upstairs
System water was released and old radiators removed priort to fitting new radiators
I have bled the system a few times to get rid of air

I have checked the boilers Status modes and it appear to follow correctly, S.0 , S.1 , S.2 etc

Expert in Vaillant required to some advice here please?

 

[ShaunCorbs]

Sounds like you need the services of a gas safe engy to check the system for you

 

[steveb21]

Sounds like you need the services of a gas safe engy to check the system for you

Yes, i am in the process of trying to locate one.

Posted my previous message to get any help on anything I might have missed checking etc.

 

[ShaunCorbs]

Yes, i am in the process of trying to locate one.

Posted my previous message to get any help on anything I might have missed checking etc.

Doesn't look like you have missed anything

Also might be worth cleaning the system if you have a few rads full of sludge

 

[steveb21]

They are brand new radiators ... The only sludge that could have filled them up would have been from the boiler, that wouldn't have been much though would it?

I just been having a play around with the system again.

Finally worked out how to turn warm start off!

Set the radiator temp to 70, it has improved the heating and radiators feel much better at bottom now. Just been around house setting the TRWs.

Bled the radiators again, no air in any of them and the water coming out is clear, not even a tint of dirt/black.

House has never been so warm ...

. I have set the thermostat in house to 18 degrees (currently showing 22)..... Will now see over night if the heating decides to randomly come on before it needs to!

 

[steveb21]

Update on this:

I dont think the temp reading on the thermostat is working. This morning with heating off all night the temp on the stat was showing as 18.5 however i have a standalone thermometer (which i know works) that was showing as 15!

Setup i have is:
Drayton Digistat +3RF Room Thermostat - Wireless
www.NoLinkingToThis/p/drayton-digistat-3rf-room-thermostat/76816

Looking at the reviews i think i may have found my source problem.

''Disappointing

8 Oct 2016
" This Digistat3 does not control temperature in a sensible way. There is in-built software that messes with the basic sensing of the temperature. My boiler is coming on for a minute and then going off again for about the same before it comes on again. This is going to wear out the control relay in very short order. I am taking it out today and replacing with a better product that senses the temperature as a thermostat should. Honestly- DO NOT BUY THIS one. "

Looks like others have had the same issues i am experiencing.

Could some one offer some advice into which unit i should replace the setup with?

(i may put this as a new thread)

 

[steveb21]

Update on this:

I dont think the temp reading on the thermostat is working. This morning with heating off all night the temp on the stat was showing as 18.5 however i have a standalone thermometer (which i know works) that was showing as 15!

Setup i have is:
Drayton Digistat +3RF Room Thermostat
Looking at the reviews i think i may have found my source problem.

''Disappointing

8 Oct 2016
" This Digistat3 does not control temperature in a sensible way. There is in-built software that messes with the basic sensing of the temperature. My boiler is coming on for a minute and then going off again for about the same before it comes on again. This is going to wear out the control relay in very short order. I am taking it out today and replacing with a better product that senses the temperature as a thermostat should. Honestly- DO NOT BUY THIS one. "

Looks like others have had the same issues i am experiencing.

Could some one offer some advice into which unit i should replace the setup with?

(i may put this as a new thread)

 

[steveb21]

Update on this:

I dont think the temp reading on the thermostat is working. This morning with heating off all night the temp on the stat was showing as 18.5 however i have a standalone thermometer (which i know works) that was showing as 15!

Setup i have is:
Drayton Digistat +3RF Room Thermostat


Looking at the reviews i think i may have found my source problem.

''Disappointing

8 Oct 2016
" This Digistat3 does not control temperature in a sensible way. There is in-built software that messes with the basic sensing of the temperature. My boiler is coming on for a minute and then going off again for about the same before it comes on again. This is going to wear out the control relay in very short order. I am taking it out today and replacing with a better product that senses the temperature as a thermostat should. Honestly- DO NOT BUY THIS one. "

Looks like others have had the same issues i am experiencing.

Could some one offer some advice into which unit i should replace the setup with?

(i may put this as a new thread)

 

[ShaunCorbs]

Do you know if you rads have been balanced from new ?

For wireless stats I use this

CM927 7 Day Wireless Programmable Thermostat - Honeywell UK Heating Controls