Problem with Halstead Ace. Help.

[erdinger007]

I looked at a halstead ace for a client which was installed by someone who did not comission the instalation properly. I performed a powerflush which resulted in a huge amount of sludge being removed. This solved the problems they had but now i have new problems. When the hot water is switched on the heating also kicks in. When the hot water is switched off the heating carries on running for a few minutes and locks out.
Once the heating switches back on after about 5 minutes of waiting it will lock out almost instantly after the burner fires up.
I dont understand how the heating can work fine with hot water running but then not work at all on its own.
I can only assume this cant be the Fan, Diverter Valve, Pump, Overheat Thermostat or the Gas Valve but i could be wrong. Please help.

 

[erdinger007]

I forgot to mention that here is no room stat and the time clock was set to ON

 

[Rob]

When the hot water is switched on the heating also kicks in.

Sounds like the diverter is letting by. I assume you mean the heating warms as the tap is being run.

When the hot water is switched off the heating carries on running for a few minutes and locks out.
Once the heating switches back on after about 5 minutes of waiting it will lock out almost instantly after the burner fires up.

Lockout on these boilers requires manual reset.
Is it really locking out or is the burner shutting off?

I dont understand how the heating can work fine with hot water running but then not work at all on its own.

The heating SHOULDN'T work with the hot water running.

 

[Agile]

There are gas related reasons why a boiler can work on DHE burt fails on CH.

It sounds as if you may not be CORGI registered so I cannot give you detailed advice for safety reasons.

It also sounds as if there is a problem with the diverter valve? Does the DHW switch turn off immediately the hot tap is turned off.

Tony

 

[erdinger007]

rob884.
The burner for central heating shuts off. If the heating does work with the HW running what can this be?
Agile.
I am CORGI registerd. I dont recall fault finding and repair being any part of my ACS training. However this has prompted me to undergo a detailed combi breakdown and repair course ASAP.

 

[erdinger007]

Agile.
The clients central heating was working fine for the last three years.

 

[Agile]

Have you checked the min and max gas valve settings?

These questions are better placed in the Combustion Chamber section of this forum!

Tony