central heating fuse blows randomly

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i have been asked to look into a boiler system that blows the 3a main fuse in the spur occasionally ie 4months apart then three fuses in a row
the system contains 4 zone valves controlling 2 hot water cylinders with individual cyl stats central heating via room stat and under floor heating with 5 manifold heads & dedicated pump controlled via two roomstats. roomstat 1 controls the zone valve, pump and room 1 manifold heads and roomstat 2 that only controls room 2 manifold heads and does not fire the boilers, UFH zone valve and pump without roomstat 1 in operation
two boilers connected in parallel and have internal pumps
i have checked the connections and they appear to be correct could this be a problem with sticking pump or valve causing overload has any 1 encouterd this type of problem before, no signs of burning
 
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i have been asked to look into a boiler system that blows the 3a main fuse in the spur occasionally ie 4months apart then three fuses in a row
the system contains 4 zone valves controlling 2 hot water cylinders with individual cyl stats central heating via room stat and under floor heating with 5 manifold heads & dedicated pump controlled via two roomstats. roomstat 1 controls the zone valve, pump and room 1 manifold heads and roomstat 2 that only controls room 2 manifold heads and does not fire the boilers, UFH zone valve and pump without roomstat 1 in operation
two boilers connected in parallel and have internal pumps
i have checked the connections and they appear to be correct could this be a problem with sticking pump or valve causing overload has any 1 encouterd this type of problem before, no signs of burning


The spur should be from an existing socket which is is on the ring main, so common sense would suggest that the ring main is being overloaded, so get the spark to check installation.
 
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The spur should be from an existing socket which is is on the ring main
Or on the ring itself.

so common sense would suggest that the ring main is being overloaded
This is incorrect - the fuse being blown is in the FCU, so it has nothing to do with the circuit.

stu1980 - check first for chafed supply cable(s) on the boiler casing(s). Also look for any signs of leaks near motorised valves or inside the boiler casing.
 
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The spur should be from an existing socket which is is on the ring main, so common sense would suggest that the ring main is being overloaded, so get the spark to check installation.
The feed for the heating electrics can be taken from anywhere; ring mains, spur, cooker, light.

Common sense would indicate that if a 3A fuse blows, it has nothing to do with a 32A ring being overloaded.
You really don't need to be an electrician to work that out, all required is very average logical thinking.
Not much hope for you then.
 
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2 boilers and UFH etc all on one 3A ?

Have you calculated the total load?
 
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