Valiant ecoTEC plus 428 - Heating not working

[dustyfrog]

Since February we are having issues with the heating of our house while the hot water for the shower works perfectly well. The actual heating the rooms, or the heating up the radiators don't work. Appears it only works for 1 or 2 radiators on the ground floor. All the other floors not much luck. In total we have 11 radiators in the house.

The house is a 3 bedroom terraced house with indoor space of ~110m2 with 9 'typical' radiators, and two wall radiators.

If I look at the Valiant on the top floor, I can see three icons show up:
- flashing fench icon
- tap icon
- circle with black filled triangle

Above the icons it shows 70c and when I press the i button on the panel the display changes and where it displayed the temperature it now shows the numbers 5. 7.

Recently we had a chemical flush of the pipings, replaced tri valves (I think they are called like that) on two radiators. The heating worked for two days and now it stopped working again. The pipes of radiators are not (piping) hot as you would expect. The pipes next to the Valiant itself are hot.

I am getting a bit distraught about the heating, really hope it will be able to get working again.

I was wondering if there any experts here that could help, if the above rings any bells? I am wondering if it could be some sensory issue? Maybe that it thinks it's already on the temperature? Currently, we put the thermostat on 30c but still no dice. Definitely, it's not 30c in the house.

If you are happen to be based in London and have the time to look into this problem and resolve this problem. Please leave me a message and we can discuss

 

[picasso]

Common problem with these boilers. the pump cant shift enough water through the heat exchanger so the boiler goes into limp mode, what setting is the pump on and what size is it ? you could also try downrating the boiler to 20 kws and see it that helps. (how to is in the install instructions)

 

[Mottie]

Blimey, 28kw for a 3 bed, 11 rad terraced house. I'm no plumber/heating engineer but surely that's a bit too much isn't it? I have an 18Kw in a 3 bed, 10 rad semi and I have rated that down to 12kw. I only put it up to 15kw when it's really cold outside.

 

[CBW]

S.7 (5.7) is pump overrun. How many motorised valves do you have?

 

[picasso]

And what is a fench icon ?

 

[Mottie]

And what is a fench icon ?

I think he means 'fence' icon. I get something like that up on mine. I think it's supposed to be a radiator.

 

[dustyfrog]

As far as I am aware there is one three way valve on the ground floor. I did a bit of reading on the site, I checked the d.0 value which appears to be 30. If I understand it correctly, I should change this to a lower value. I think it's suggested to change this 15-20kW? At this might help with the boiler behaving better?

If I try to change this myself could this make the problem worse or break the boiler?

> @picasso what setting is the pump on and what size is it ?

Sorry, I have to admit my experience is limited, and have to ask for clarification what you are asking for.

 

[picasso]

Drop the d0 to 20kws, it wont break or damage your boiler, post a pic of the pump and any buttons or dials on it.

 

[Mottie]

If I understand it correctly, I should change this to a lower value. I think it's suggested to change this 15-20kW?

Try setting it to 15. You won't **** anything up. You can always change it back in seconds.

 

[dustyfrog]

Thank you, that's a relieve to hear. I will definitely try that shortly.

Regarding your pump question, I think, you mean, the following apparatus Grundfos Alpha2L next to the Valiant. Am I correct?

Water-pump

• dustyfrog
• 25 Apr 2022

My apologies for my lack of understanding of heating systems and such

 

[picasso]

Pumps fine , its on the highest setting.

 

[CBW]

As far as I am aware there is one three way valve on the ground floor.

This could be sending it round the hot water circuit instead of the radiators.

 

[dustyfrog]

Great, I will try to lower that setting and let you know. I would be delighted if that solves the problem!
Regarding changing, from another forum topic, I understood this are the steps:

1. Press the "I" and "+" keys simultaneously.
2. The display shows "d.O"
3. Press the "i" key. The display shows the relevant
4. diagnostic information.
5. Use the "+" or "-" keys to change the value (display flashes).
6. Save the new value by holding down the "i" key for
7. approx. 5 seconds until the display no longer flashes.

This could be sending it round the hot water circuit instead of the radiators.​

Maybe a stupid question but if a few radiators are luke warm on the ground floor, would this still be the case? Could the above suggestion of changing the boiler setting
affect this somehow?

Anything else I could try besides that if it wouldn't be working?

 

[picasso]

Turn off the hot water on the programmer, set the d0 to 20 kws and report back.

 

[Mottie]

On my 418, I think I have to enter 17 to get into the engineers mode before I can change the max output setting.