Storage heater tripping

peterhyper · Oct 18, 2019

I went to a call regarding a dimplex storage heater not coming on during economy 7 hours. I did the basic tests and the storage heater is on an old board with cartridge fuses, and the fuse was fine and the FCU switch was also okay. I connected the heater to a 13 amp plug and every time it was turned on it blew the adapter mcb in a seperate old 3036 board (no RCD).

I am a little confused because the storage heater is on a seperate board and that also has another storage heater connected to it which is working fine during economy 7, so the board is firing up okay. If the heater immediately blows every time it goes on when plugged in the second board why hasn't it blown the cartridge fuse in the economy 7 board?

I felt sorry for the elderly lady and would like to get her heater up and running, so any suggestions of anything obvious I've missed is appreciated (no warranty is left on the heater).

telectrix · Oct 18, 2019

thoorough test of the circuit from eco7 board to heater outlet. you may find a fault there so that the faulty heater does nort blow fuse in eco CU.

davesparks · Oct 18, 2019

What tests did you carry out and what were the results?

What size mcb is tripping? What is the power rating of the storage heater?

Have you confirmed that there is a fuse in the storage heater board and it hasn't been replaced with a bit of wire/nail?

littlespark · Oct 18, 2019

Simple continuity tests through the storage heater, and insulation tests to the metal body.
Elements will give a reading in ohms.... ie, not zero, and not high Mega ohms… If any element is duff it will be open, or short circuit.

snowhead · Oct 18, 2019

When you're fault finding it's very easy to get distracted from the original problem.

Ignore the, Why it didn't blow the E.7 fuse, you may find out why later.

Back to the problem;
The heater didn't work, when on E.7
The E7 fuse is good.
Straight to the heater, as above check continuity through heater and to earth.
(p.s, you'll probably find the Flex live had burnt off the connector and twisting the flex to put a plug on it has caused it to touch earth).
If heater etc is O.K check continuity of flex back to and including the isolator.

peterhyper · Oct 18, 2019

Thanks for the replies guys. The 15amp cartridge fuse is as it should be.

It's a 3kw heater. I haven't done any tests its circuit due to it instantly blowing the 30amp mcb on the main board, so it indicates the issue is with the heater and not the circuit, but it's odd that it's not blowing the fuse in the economy 7 Fuseboard and that's where I'm confused (although it doesn't take much to confuse me).

davesparks · Oct 18, 2019

peterhyper said:
Thanks for the replies guys. The 15amp cartridge fuse is as it should be.

It's a 3kw heater. I haven't done any tests its circuit due to it instantly blowing the 30amp mcb on the main board, so it indicates the issue is with the heater and not the circuit, but it's odd that it's not blowing the fuse in the economy 7 Fuseboard and that's where I'm confused (although it doesn't take much to confuse me).

Tripping the MCB suggest that something has changed when you fitted a plug to it to create a fault. As @snowhead has suggested it could be a poor connection in the heater which move when you moved the flex.

Have you checked the connections inside the heater?

richy3333 · Oct 18, 2019

Regardless of the problem good luck getting spares since LOT 20 came into being. It does sound as though there is something wrong with the heater.

peterhyper · Oct 18, 2019

davesparks said:
Tripping the MCB suggest that something has changed when you fitted a plug to it to create a fault. As @snowhead has suggested it could be a poor connection in the heater which move when you moved the flex.

Have you checked the connections inside the heater?

I didn't open the heater as apart from checking the obvious things I am frankly clueless and have only ever installed them and not repaired them, plus the lady didn't know at the time if it was still under warranty (it's not).

I will pop back next week and check inside the heater.