back boiler tripping out electrics

[nublet]

i have a back boiler installed in my gf's property but i'm unaware as to what make or model it is as i can't see any data plates saying what it is.

all i can tell you is its a randall 30 20P controller.

if i turn on the heating or hot water the boiler fires up runs for about 5 mins then the RCB kicks in and i lose power to the house.

This has just started to happen after the summer and the boiler not being in use for roughly 3 months.

any ideas?

ps turns out its a honeywell housewarmer spectacular S

 

[gas4you]

I would look at the pump first.

 

[nublet]

i have had a look at the pump i can hear it whirling away i isolated power to it and have checked the power and i'm getting 230v across the live and neut.

i did notice that none of the pipes were warming at all when the boiler ran, it lasted about 4 mins be4 blowing again.

 

[gas4you]

Try bleeding a upstairs rad and see if you get air and then water out.

I have had one occurence where the cold feed to the system had blocked and the pump was running dry and this kept tripping every thing.

If the pump is spinning properly then the pipes either side should be getting warm if there is water in them.

 

[nublet]

k dave done that i have 4 rads upstairs all in a sorry state 2 the bleed vents r knackered so couldn't bleed em.

1 i bled bit of air then water other got water straight away. the rads were slightly warm to the touch but nothing fantastic.

now its just come into my mind that i was messing with the heating system several months ago as it became apparant there is a tiny leak in the system.

i tied up the ball cock in the attic marked on the side of the tank were the water was and left it for about 4 weeks. Heating wasn't used in this period and after that time i went bk up into the attic and noticed the tank was near empty. ( reason for this was we have damp appearing on a wall with a rad on but i couldn't find the exact spot for the leak )

anyway i realised the ball cock let the system fill back up and forgot about it.

has this any bearing on current problem?

 

[gas_man_gaz]

ive had it a few times where the wire for the back boiler has got burnt and starts tripping the electrics, mite be worth a check

 

[nublet]

checked the wires to the boiler i can't see anything obvious thats wrong no smell of burnt wires no scarring on the plastic sleeves....

 

[JohnD]

you have not said if the pump is circulating the water

you may have had sediment cause a blockage, or seize the pump

the jammed bleed keys can be removed, with their plugs, using one of these

then you can fit a new one

what colour is the water that you bleed out?

If the RCD is tripping it is probably a water leak dripping on to an electrical part. This might be at the pump, possibly the 3-way valve, possibly in the boiler electrics wherever they are.

 

[nublet]

i dont know if the water is circulating though the upstairs rads started to get warm be4 the power cut off again.

the water was dark brown the system was cleaned only last year with x400 and had x100 put into it.

 

[JohnD]

if you feel the pipes on either side of the pump at start up you will be able to tell if hot water is flowing through it.

 

[nublet]

pipes were cold

 

[JohnD]

take out the silver screw in the middle of the pump. see if water drips out. see if you can turn the spindle with a screwdriver.

If you can do it safely, use your multimeter to see if power is being delivered to the pump

 

[nublet]

there is no silver screw in the middle of the pump is not like a danfoss or anything its a really old commadore pump never seen one like it be4 tbh

i've checked the wiring when the power is isolated i was getting 230v across it do u suggest i check it whilst live?

 

[namsag]

Simple way for you as a diyer to check if pump is causing it is to disconect the pump wires completely and then run the system again and see if it trips if it doesn`t you know it is the pump if it still trips its something else

 

[gas4you]

if the water is dark brown then it wasn't cleaned out properly last year