Valliant Eco tec Plus 937 cond combi CH problem

[Andyk78]

Hi chaps,

Just completing soon on our first house and been round today to check a few things and noticed the radiators aren't very hot just luke warm at best
I had a mess round with it and seems to fire up ok and the water is hot and water pressure through taps seems good with a hard and fast flow rate.
However the radiators just don't get hot enough?
No error messages dispalying but did notice that the pressure on the display was at 0.9bar and when I turned the boiler off and on again and set the heating to full whack the 0.9 went down to 0.8 then 0.7 and then seemd to fluctuate back up to 0.9 and back to 0.7.
Could this be the problem and how can get get the radiators beaming hot again?
Also as a side matter i think the vent flue on the gable is upside down, would this be a problem leaving it the way it is.

Help appreciated

 

[twgas]

I would sggest increasing the system pressure to 1.2ish bar and see how it is.
What makes you think the flue terminal is upside-down.

 

[Andyk78]

Thanks Mick, how do I increase the pressure on this unit?
I think the flue is upside as the bottom bit of the flue sticks out further than the top and I thought it was supposed to be the other way round (hope I've explained that right haha)
Would this need to be rectified or is it ok to leave as it is if it's upside down?

 

[twgas]

There should, somewhere be a thing like

 

[Andyk78]

Thanks, I will take a look for it once I'm back round there later this week.
Any ideas on the upside vent if it is upside down that is?

 

[mickyg]

you will have a built in filling loop under the boiler. 2 grey handles. What controls are installed? it may have weather compensation in which case its working correctly, or the control knob is turned down or broken. If you turn the CH knob the display should show the temp set changing, if not its broke. Have no idea what you are talking about regards the terminal.

this is a vaillant flue the correct way up

Untitled

• mickyg
• 19 Aug 2009
• 7

 

[twgas]

If you can post a pic of the flue it might help

 

[dreadnoughtheating]

Is(are?) there 'weather compensation' controls? If yes, and the outside air temp is high enough water temp to radiator circuit ought to be low... hence low temp radiators, or of course air in the top section of radiators, requiring venting.

Dreadnought

 

[Andyk78]

Sorry, trying to get a couple of pictures on but not working? The upload image button is greyed out so can't upload a photo???

 

[Andyk78]

Thanks all, ok had to do it from the phone as wont on tablet.
View media item 60129 View media item 60130

The flue picture is off the web as I didn't take a photo whilst there, the flue is the same as pictures more or less but upside down for what you see in the picture so the plastic is cut at an angle making the top lip for want of a better word stick out further than the bottom (as pictured). But mine is the other way around so bottom sticks out further than top. Hard to put into words but have done my best here

Secondly there is a little valliant panel as pictured below on the wall. And in the hallway there is a digital thermostat.
Another shot of the boiler, Jesus this things like a deep freezer hanging from the wall haha
View media item 60131
And this is the exact thermostat as pictured/ or is this the weather compensator you mentioned?
View media item 60132

 

[Andyk78]

Where have you all gone

 

[ALEC1]

yes the radiators get hot enough.. but the system needs to be left on to do its stuff..

This is a VRC 400 weather compensator...a great investment..


after turning the system on from cold, you will need to raise the 'target" room temperature on the controller for a while.


the system inversely follows the outside temperature, the colder it is the hotter the radiators, and vv..

you need to read the instruction books, or ring vaillant who will explain it..

 

[Andyk78]

Thanks, will take a look - just to clear though, so the outside weather will always determine how hot or cold my hearing should be in the house? And I can't override this? Also does the pressure now NOT need adjusting? It's just that from doing a little looking around it seems the system
should generally run at 1.2 - 1-5bar?

 

[ALEC1]

Yes of course you can adjust it any way you see fit, why would any one want an un adjustable heating system?

 

[Andyk78]

To be honest, I have started to look at the online user manual this morning for the boiler and now the weather comp and its all starting to become a headache. Weather compensator talking about heating curves etc....wtf!!
I just want to set a time and have my heating come on a couple of times a day at a temp of my choice. Call me old school but just want a simple heating system haha. This maybe the all bells and whistles system and I'm sure it is for plumbers who fit these things and know how to use them as part of their daily job fitting them. But for me a 1st time homeowner it seems like a lot hassle. May even sell it and get something simpler as I'm already not liking the sound of it, just want a simplified set up that does the same job