odd problem on boiler startup ecoTec plus 428

[williams]

ScottishGman.....did sit down with the installers from day one and worked out the output required for the rads in place. most rads are big doubles. Its a 5 bed Victorian detached with big rooms and high ceilings.
and why would this be giving a problem now when it was working fine last year?

 

[Dan Robinson]

In the same way you knees creak as you get older.

Boler is becoming less able to cope with what could be a poorly designed system.

I agree it is oversized, btu not by that much.

I would suggest the pump is too small for the job (I think those Grunny's are pants anyway).

The pump I pictured was a pish take - it is an industrial one - these boilers are renowned for needing monster heating pumps.

 

[Dan Robinson]

Edit - just twigged it is the old UPS, not UPS2 - so not pants, but still insufficient.

 

[Agile]

But the question still arises why was it working OK before!

Are there speed settings on pump? Which one is it on?

What is the pump power rating? This will be in "w" for watts!

Tony

 

[williams]

thats the question i'm askinh agile.....the CH boiler,system and the pump are basically a couple of years old, rads have been replaced, system flushed and magnaclean installed

i've put the pump details in a previous post agile, scroll up a few posts, there are 3 speed setting and its on 3

 

[Agile]

Yes, I saw that. But I still don't know what the current and power are.

To see if the flow is adequate you would need to measure the flow and return temperatures when the boiler is firing. Ideally while the system is warming up from cold. Should not be too much more than 10 C difference.

You can see what the boiler THINKS they are by looking at the d40 and d41 readings on the display. But the proper engineer's way is to actually measure them on the pipes.

If they are too wide ( more than about 20 C ) then the boiler will think there is a fault.

If the pump is suspected then you will need to measure the current it is taking as a first test.

Tony

 

[Dan Robinson]

Its a UPS 15-60 Tony.

 

[ScottishGasMan]

Ok. So to get the boiler to hit an S.53 blocking code, you need the flow and return temperatures to be either 30 or 35*c apart (can't remember exactly) if you have the correct flow through the boiler you will get exactly 20*c difference when burner is at full power in comparison.

Last year you could have been sitting with a difference as much as 34*c and now the second it hits 35 it will fault to s.53 and go to minimum burner output.

This does not mean the boiler and installation was ok last year. This means whatever's wrong may only be becoming noticeable this year.

Has the boiler been piped in 28mm pipe or 22mm? Is there an automatic bypass valve fitted ?

 

[ScottishGasMan]

Yes, I saw that. But I still don't know what the current and power are.

To see if the flow is adequate you would need to measure the flow and return temperatures when the boiler is firing. Ideally while the system is warming up from cold. Should not be too much more than 10 C difference.

You can see what the boiler THINKS they are by looking at the d40 and d41 readings on the display. But the proper engineer's way is to actually measure them on the pipes.

If they are too wide ( more than about 20 C ) then the boiler will think there is a fault.

If the pump is suspected then you will need to measure the current it is taking as a first test.

Tony

10 degrees was for old standard efficiency boilers (11 actually)

And the ntc's used to measure the pipe temps in these boilers are imo the best you'll find in any boiler and more than adequate to give you spot on d40/41 flow/return readings.