Time to call an engineer?

[scotzman]

Hi Folks,

Been having a few problems with my central heating lately, and I have exhausted all bar one possible cause, Cold Feed Blockage, however I'm not convinced its this due to the clarity of the water. When I drained the system at the beginning of the week, it was dark, but not black and no sludge so I'm not convinced its that.

Few months ago, boiler (Ideal FF240) was cycling every 3-5 seconds and a new fan solved this problem. Up until last week, it was working as it should.

However, last week it wasn't staying on, and following some advice on here, put the system into "Pump Fail Mode", boiler thermostat low, hot water tank thermostat high, Mid Position Valve put manually into Mid.

As this worked, it reinforced the suggestion the pump has gone, so at the beginning of the week, a new one was put it.

This didn't resolve the issue, so I checked the actuator (Mid Way Valve) for power and it seem the board wasn't working entirely properly. So this morning, changed the Mid Way Valve, the Hot Water Thermostat (Was crusty and brittle) and the room thermostat.

However, it is still the same, recycling every 10 seconds. During the course of the week the cycling has fluctuated between 5 and 20 seconds however it is still short cycling far more than I would expect.


So in short:

New Fan - Fitted by GSR
New Pump
New 3-Way Valve
New Hot Water Thermostat
New Room Thermostat

I'm out of idea's and legal skillset, so was thinking about taking out a maintenance contract with a service included rather than just get a GSR out for a look.

Any advice before I take that final step would be greatly appreciated.

Thanks

Dougie

 

[Agile]

If the boiler is working correctly then short cycling will be caused by a lack of flow through it.

With the boiler firing and the correct flow, the temperature differential will be about 11 C.

So measure the differential with the boiler firing.

Even a hand held measurement will help to assess the problem.

But with all your DIY attempts, I would not discount a boiler fault.

Tony

 

[scotzman]

Thanks for the reply Tony, where is the best place to check the differential? Sorry if that sounds a dumb question?

I had actually contemplated getting a IR Temp Gauge to balance the system.

It was suggested to me to actually hook up the cold water mains to the cold water feed to power flush the system to remove any potential blockages, just to eliminate the possibility...would you suggest this as an appropriate course of action?

Cheers

Dougie

 

[Agile]

You need to measure on the flow and return pipes on the boiler.

An IR thermometer is virtually useless and a contact type should be used for accurate measurements.

Tony

 

[scotzman]

Thanks Tony

And I take it if it is more than 11, then there is a flow issue?

Dougie