Help needed - aberdeenshire scotland - heatre sadia megaflo - ch

[Jodi Thomson]

Hi Folks

In need of some help with the aforementioned cylinder.

We installed a Heatrea Sadia Megaflo - Pre-plumbed unit along with a Worcester External Condensing Boiler running on Oil. When all was started the HW worked away perfect and still is, but the CH has never worked correctly. For some reason when you turn the CH on, it heats some rads nearest to the boiler, but not the ones farthest away, the system has been bled for any air, and balanced but still its the same. We then removed all the rads and power washed them all out and put them back on, filled up, switched on and still the same. A second plumber then advised to replace all the pipework to the rads, this was done, all exisiting copper pipework was replaced with new plastic pipe at 22mm reducing to 15mm onto rads. Filled system, started, still the same problem. We then tested all the rads on there own and each rad worked perfectly, switch them all on and the problem starts all over again. We then phoned and brought in another plumber, he checked over the whole system, and thought we were not getting enough flow to the rads, therefore advised we change the new Grundos Pump with another. We did this, and still the same problem. Any advise would be great and much apprecaited, as it's driving me up the wall!!!

 

[justlead1]

Hi. I am assuming there is a motorized valve that diverts the heated water where its needed? Is it working correctly? Perhaps trying it on a manual setting. It must be a restriction of some kind providing the boiler is capable of producing the heating load and the pipework sized correctly.

 

[Jodi Thomson]

Hi yeah the motorised valve opens on demand for CH, via danfoss electronic room thermostat and programmable time clock

 

[Toddyplumb]

Guys and Gals read this in conjunction with other post Heatrea Sadia and Grundfos pump I think someone local might like to have a look !

 

[Jodi Thomson]

Hi Folks

I have been speaking to Heatrae Sadia this morning about getting an engineer out to have a look at the tank. They have advised me that if its a CH problem then the problem is with my condensing boiler not the megaflo. when the megaflo asks for CH the zone valve opens and the boiler kicks in, runs for 2 mins and then shuts down again? any ideas. I guess the boiler must have to run for longer than 2 mins to reach temp?

 

[dontknowitall]

Is it worth getting Heatrae Sadia AND Worcester out on the same day working WITH each other? Then you can watch them like a tennis match while Heatrae says it's the boiler and Worcester says it's the cylinder. Joking apart, between them and together, they should be able to work it out. (And if they don't it should be quite entertaining listening to them pass the blame!)

It might cost you but this problem looks as if it's driving you and other plumbers up the wall. Hope it sorts soon.

 

[Toddyplumb]

But the boiler runs for longer than 2 mins when on hot water ?

 

[Jodi Thomson]

Switching the system off now, to let it cool down, then we'll switch it back on and the megaflo will ask the boiler for HW and we will time the boiler.

 

[Gray0689]

If you put time clock to CH only without hot water isit still just running for 2 mins?

 

[tamz]

This is a bit of a stab in the dark here but check your wiring carefully for a broken or loose neutral wire somewhere.

I had a problem like this years back on a boiler swap that was working perfectly before i started. I was climbing the walls trying to figure it out. I can't remember now exactly where it was but it was down to a broken neutral wire.

It might come back to me

 

[wards]

i would put my money on circulation problem on ch side,it is working fine on hw mode so boiler and megaflow both working,when in ch mode it is going just around the boiler hence 2 mins later the boiler is up to temp and consequently shuts down,just my thoughts,HTH.

 

[Jodi Thomson]

this is wot we are thinking also, we received a telephone number from a senior member here on he forum for a engineer in aberdeen. We gave him a call and hes going to come out this week. Theres nothing worse than looking over someone else shoddy work! Hopefully he'll be able to get us sorted out. Circulation makes sense, but it all worked before on the old system, and with new run of pipes you woulnt expect this problem to appear.