Electramate 2000 9kW

I have recently been asked to have a look at a problem ( No Hot Water / No Heating ) with an Electramate 2000 / 9kW Model.
On visual inspection found Top Left Relay had melted ( High Resistance Joint ) and replaced 25A relay.

NEW 25A RELAY

Central Heating came on but H/W did not instantly come out as I assumed the Heat Store would have to take an Overnight Charge as the whole system was stone cold.

RESET THERMAL OVERHEAT ON ELEMENT ( OPERATED AGAIN ) after a short period.

No Switched Live to the Lower Pump ( Boiler Pump ) evident.

I tried to contact the Gledhill Technical Line (£1/MIN) on various occasions over ( 2 DAYS ) but the line just rang out.

On complaining to the Gledhill Sales Representative I had a call from an (Ex Engineer from Gledhill) who asked me to check the PCB.

As the ( 2nd Bottom LED ) on the PCB was not illuminated was told : ( FAULTY PCB )
Checked Pump as water evident ( ADVISED REPLACEMENT PUMP )

Fitted :

NEW HEX PCB
NEW GRUNFOS PUMP
NEW TOP ISOLATOR VALVE
NEW RED PRESSURE RELIEF VALVE

Fitted all of the above.

Isolated Water via 15mm Filling Loop
Drained / Removed Pr via PRV ( Pressure Lower + Water empty )
Replaced Pump / Top Valve ( Lower Pump ) Non Return Valve on Top

Replaced Pressure Relief Valve

Cleaned Automatic Air Vent on Top

Turned on Water Supply - Stopped just over 1 BAR.

HEX P.C.B

Remove old PCB / Replace Leads on New PCB
PUT JUMPER ON (PIN 5)
Start up - Flashing Display
Display Stops Flashing
Isolate Supply (REMOVE FROM 5) and Replace Jumpers on (2+4)
Reinstate Supply

On initial Start Up - Overheat on Element tripped out AGAIN. ( Boiling hot as is the lower pump )

MY QUERY is ; Why is the Non Return Valve on the input of the pump (TOP PORT) when the 2 UpperPumps above have their NON RETURN VALVES on the BOTTOM PORTS ?
All the pumps are facing the same direction but the NRV's are on the 2 upper pump outputs ie ( BOTTOM )
Surely there would be no flow on the Lower Pump ?
Can anyone explain ?

You say the non return valve is on the input / inlet side of the pump.
It needs to be in the direction of the flow of the pump.
When the pump stop it prevents it from reversing
I thought the tech line was 60p a minute, has it gone up?
PCB did you check for fault codes.
And the bar display?
Mike

"MY QUERY is ; Why is the Non Return Valve on the input of the pump (TOP PORT) when the 2 UpperPumps above have their NON RETURN VALVES on the BOTTOM PORTS ?"

Because it is assembled wrongly. The NRV has to go on the outlet of the pump but you have the pump in backwards. The two higher pumps are pumping downwards, with their outlets at the bottom, so the NRVs go on bottom, and the bottom pump pumps upwards, so the pump outlet and NRV go on the top of the pump.

Sounds to me as though you have fitted the lower pump pumping downwards with the NRV on the inlet and pointing upwards. The pump will be unable to pump anything against the closed NRV as it is facing the wrong way. This will lead to rapid overheating of the heater canister and tripping of the overheat thermostat.

Hope that helps,
Mike

I thought this would be the answer

I did change the NRV to the output of the pump however I have got it pumping in the downwards direction as in with the other pumps as I assumed it had been assembled incorrectly 6/8 months ago.

My logic was that on the images on the Manual ( via Internet ) it does not show the pump connection unit on the bottom and it did not show the NRV either if you look closely.

Which leads me to think it was assembled incorrectly when they took the Manual picture originally.

The boiler is working ok at the moment, however it is pumping downwards, so not being an expert on this particular model, what detrimental effect will it have pumping backwards or downwards ?

Also, I did not test the PCB for fault codes as it was a new PCB, is there any thing else I should do or address and how exactly do you do these ?

Sorry, forgot to reply about the Technical Line. Most of the time it is more advantageous to phone whilst on site. However, via a mobile it is over £ 1.00.
Worth every penny if you are not familiar with the usual faults but no good at all if you can't get hold of them.
I have posted here because this gives you time to divulge valuable information and after speaking to Mike, thought it fair to put my input into this site as well as rectifying the problem I have, of course.