Vaillant Ecotec plus 630 error S7

[Mamps]

Hi I hope someone can help.

I have an Vaillant Ecotec plus 630 boiler that runs my underfloor heating and my 10 radiators. in a 3/4 bedroom semi-det house.

The radiators don't seem to get very hot - i've set the thermostat to 25, but its not getting warmer than around 16

Looking at the boiler, i see the following pattern.

I get S7 error - radiator sign flashing.
Then after around 10 mins, i get the following sequence:
S2, S1, S3, S4 - radiator sign NOT flashing.
Stays on S4 for around 5 mins
Then whizzes past S5 & S6 to S7 - radiator sign flashing again.

Anyone know what the problem is?
Is it the pump?

Someone said i need to get a powerflush - that theres a blockage somewhere and it makes my boiler work too hard, thats why I'm getting the pump problem...

 

[bobw1956]

S codes are not error codes,they are status codes S7=pump over run.

S1-4 = Ignition sequence S4 Boiler on

Can you confirm boiler ignites at S4

 

[Mamps]

Hi, thanks for the response.

Yes, it ignites - theres a solid flame sign and the rads are getting warm - not hot.

 

[Mamps]

have turned 2 radiators off now in the rooms i'm not using, seems to have helped by 1 degree..

I also get the flashing radiator sign when theres an S8 status

 

[Mamps]

Any ideas out there?

Do I need to get my rads power flushed?

Any settings I can change?

what does S 7 - pump overrun mean?

Is my pump not able to cope?

 

[hazetimesfive]

pump overrun is where the pump continues running after the boiler reaches the required temperature and shuts off, this is to dissipate the heat from the boiler and stop the water from boiling.

 

[hazetimesfive]

what to the flow and return pipes feel like when the boiler reaches S7

 

[Mamps]

When running at S 4 both pipes are piping hot the flow pipe on the left is almost too hot to touch and the return pipe is very hot but not as hot as flow pipe.
When in S7, they both are still hot (hotter than my rads) i wouldn't call them warm - still hot.

Then its re-ignites etc back to S 4 and they're piping hot again left flow pip almost too hot to touch.

 

[mickyg]

its not circulating. or if it is its bypasing somewhere. Boiler is grossly oversized anyway, who on earth decided on 30kw???

 

[Mamps]

Then could it be true that my rads need a power flush then if it may not be circulating?

what do i need to get done to fix the problem?

My plumbers who fitted the whole kit decided the spec.
It does also run the underfloor heating in the extension.

was only fitted 2 years ago.

 

[Agile]

What experience did your plumbers have?

Did they speak English?

Did they complete the Benchmark Certificate withgb a Gas Safe number?

Did they calculate the whole house heat loss? Usually about 10-16 kW for a semi !

Tony

 

[hazetimesfive]

who calculates heat loss, 99% customers want rads that 'fill the gap' and bugger everything else..

cant remember the last time they asked me what they should be having.

 

[hazetimesfive]

how is the UFH connected exactly

 

[mickyg]

i very much doubt a powerflush is the cure. Get a proper heating engineer in to diagnose the problem correctly.

 

[Mamps]

I'm not a plumber, so trusted them to spec what i needed for the house.

I'm not sure how exactly the UFH is connected. Theres a separate manifold.

I'll post a photo if it will help?