While reclining in my bath the other day (I do all my best thinking
there) I realised that our boiler, installed a few short years ago was
designed to pump on for 15 minutes after the flame went out. The Corgi
plumber wired it wrongly, so that the pump ran all the time the central
heating timer said give me heat. I can live with this, as he said that a
pump that runs all the time, is far better than one that starts and
stops all day.

Now to my question.

As I am now using the timer to optimise the running time of the boiler,
it may prevent the boiler from running the pump for the 15 minutes it
needs after the flame goes out. Will this do any harm?

Boiler is a Baxi Solo PFL 30/80

Dave

"Dave" wrote in message
...
While reclining in my bath the other day (I do all my best thinking there)
I realised that our boiler, installed a few short years ago was designed
to pump on for 15 minutes after the flame went out. The Corgi plumber
wired it wrongly, so that the pump ran all the time the central heating
timer said give me heat. I can live with this, as he said that a pump that
runs all the time, is far better than one that starts and stops all day.

Now to my question.

As I am now using the timer to optimise the running time of the boiler, it
may prevent the boiler from running the pump for the 15 minutes it needs
after the flame goes out. Will this do any harm?

Boiler is a Baxi Solo PFL 30/80

Dave



Read the installation guide for the boiler.
If it requires the pump to run-on, then let it.

This will require 2 supplies to the boiler:
1) a constant mains supply to run the pump for the required time;
2) a 'demand' signal to fire the burner.

The pump does not need to run the whole time - just the run-on time required
by the boiler. The boiler will normally handle this. Simply provide the
necessary supplies and let the boiler get on with it.

( I've not read the details of your boiler, just general advice.. )


--
Ron

In article ,
Dave wrote:
As I am now using the timer to optimise the running time of the boiler,
it may prevent the boiler from running the pump for the 15 minutes it
needs after the flame goes out. Will this do any harm?

Are you sure it's 15 minutes? The actual 'need' is to equalise the heat
exchanger temperature to prevent boiling when the pump stops. Efficiency
would demand you get all useful heat out of it - I suppose. But neither
would take 15 minutes.

--
*The modem is the message *

Dave Plowman London SW
To e-mail, change noise into sound.

In message , "Dave Plowman (News)"
writes
In article ,
Dave wrote:
As I am now using the timer to optimise the running time of the boiler,
it may prevent the boiler from running the pump for the 15 minutes it
needs after the flame goes out. Will this do any harm?

Are you sure it's 15 minutes? The actual 'need' is to equalise the heat
exchanger temperature to prevent boiling when the pump stops. Efficiency
would demand you get all useful heat out of it - I suppose. But neither
would take 15 minutes.

The Baxi Solo 2 has about a 10 min o/run, the Potterton Suprima has 20
mins

15 mins sits in the middle


--
geoff

In article ,
geoff wrote:
In message , "Dave Plowman (News)"
writes
In article ,
Dave wrote:
As I am now using the timer to optimise the running time of the
boiler, it may prevent the boiler from running the pump for the 15
minutes it needs after the flame goes out. Will this do any harm?

Are you sure it's 15 minutes? The actual 'need' is to equalise the heat
exchanger temperature to prevent boiling when the pump stops.
Efficiency would demand you get all useful heat out of it - I suppose.
But neither would take 15 minutes.

The Baxi Solo 2 has about a 10 min o/run, the Potterton Suprima has 20
mins

15 mins sits in the middle

I'm amazed. I fitted a home made one to my old Potterton Kingfisher which
had a massive cast iron heat exchanger - and 5 minutes did it. Of course
this was dumping the heat into the rads not fitted with TRVs - thinking
on, it would be different if just using a bypass circuit.

--
*Why can't women put on mascara with their mouth closed?

Dave Plowman London SW
To e-mail, change noise into sound.