Ideal Classic 40ff

[southseapirate1]

Hi

i'm a very newly qualified Gas Safe Engineer. I've not really touched on installs or the wet side either just servicing.

I have at home a Ideal Classic 40ff. It has it's pump on top of the boiler with a small expansion vessel, no FE tank in loft thus a pressurised system. Have a mega flow in the airing cupboard. Two valve system one for hw one for ch (snvic 4 wire valves) spring loaded so once demand is off they wind back to the off position(shut)

The problem i have is the pump sometimes runs constsantly after the boiler has shut down and there is no demand for heating or hot water from the timer/programmer also the hot water is hotter then the setting on the cylinder thermostat.

I worked out that the ch mv was working perfectly no dramas however the hw mv didn't seem to wind back after the call for hw was finished and we we are in bed keeps us awake it sa nightmare. I have changed the sunvic mv thinking that may have been vaulty and handnt been moving back to it's closed positon thus taking the live feed away from the pump and making it stop. I also changed the thermostat on the mega flow cylinder, set the temp to 50 degrees lesser than normal to bring the temp down hope if there was maybe a pump over run(which I don't think there is after looking at the ideal manual unless its part of the pump fitted on the top and the classic man instructions don't state that. However hot water temp still really hot, well hotter than wud be expected on temp stat, and pump still runs at night apart from tonight everything is quiet heating and hot water has no demand and the boiler is off woo hoo. wierd!!

I'm at a dead end and to add when the pump was running constantly every so often very rarely the boiler wud turn on establish a flame and then shut down again straight after!!! I'm starting to go mad. one more thing there is a balancing line in the airing cupboard(connect the heating side to the hot water does anyone know what position it should be in too????

any help would be greatly appreciated

Dave

 

[Tibbot]

After demand ceases check if you have 240V/ac at the orange wire on the suspect valve. If so it's faulty and that's what's powering pump & boiler continuously.

 

[southseapirate1]

Hi Tibbot,

Many thanks for you reply, I will endenvour to check it tomorrow and get back to you with the outcome. Do you have any idea whether the the balancing Vv shut be open, shut 50% or shut etc etc?

Regards

 

[Tibbot]

If you mean one on the cylinder primary return then it must open or you'll get no hot water, but strangled enough not to starve the CH circuit.

 

[onlyfitidealboilers]

God help your customers!! two port will be sticking.

 

[southseapirate1]

Hi onlyfitidealboilers,

With all due respect newbies have to start somewhere. As you know when you do your ACS it's purely on the gas side. Of course i'm very willing to learn and when time permits do the wet side. Gaining information and direction for a problem I have in my house from chaps who are very knowledgable and experienced can only be a good thing.

I have changed the MV already so it seems its a dud until I've put my Vol meter to confirm.

Thank you for you advice & support its greatly appreciated.

 

[onlyfitidealboilers]

what make of valve is it?

i know you have to start somewhere, what training did you do ??

 

[southseapirate1]

I'ts a sunvic SZ 2301.

 

[southseapirate1]

Did purely gas, boilers, flues, safety devices, gas rates safe and unsafe stituations but nothing on heating systems.

 

[onlyfitidealboilers]

Oh your not an apprentice then? adult career changer?

crap trade now..

 

[southseapirate1]

Yes I'm 40 did my training at a site called Steve Willis Training Center it's in Hampshire then work placement to build a portfolio etc.

 

[southseapirate1]

The pump is running and all demand has ceased plus the hot water is 80 degrees even though the newly fitted cylinder thermostat is set to 50 degrees. So until I have checked the MV for 240Vs I presume the newly fitted Vv maybe faulty.