Programmer Voltage To Boiler Only 70Volts?

[bacoms]

Hi all,

Cutting a long story short, I've let my house out via a letting agency while I'm away. Recently the tenants found that the CH did not come on and notified the agent who arranged a visit by an engineer.

The engineer claimed that the voltage being supplied to the boiler by the programmer was only 70volts, therefore the programmer was faulty. Subsequently he has replaced the programmer and the thermostat with a combined wireless programmer/thermostat, as he wasn't familar with what was there already.

Does anyone know what sort of problem with the programmer would cause it to only output 70V (sorry I can't remember the make & model of the programmer)? I would have thought that it would either output 240V or 0V.

I'm no expert but it all seems a bit odd.

 

[Sharpend]

It sounds to me as though the "cough" engineer really wasn't worth his "cough" title?!

What sort of system do you have? Combi, system boiler with hot water tank? Do you know how many motorised valves there were?

 

[bacoms]

What sort of system do you have? Combi, system boiler with hot water tank? Do you know how many motorised valves there were?

Thanks for replying.

The boiler is a combi, one of the Worcester Bosch Greenstar range. I can't remember the model but it serves 9 rads. in a 3-bedroom house.

I don't recall any motorised valves external to the boiler.

 

[ProDave]

Well the programmer could have been faulty, a faulty relay inside it for instance.

What bugs me is why he felt the need to replace a programmer with a programmable thermostat. Sounds like "making work" to me.

 

[SPECIAL LOCATION]

The engineer claimed that the voltage being supplied to the boiler by the programmer was only 70volts, therefore the programmer was faulty.

Subsequently he has replaced the programmer and the thermostat with a combined wireless programmer/thermostat, as he wasn't familar with what was there already.

Does anyone know what sort of problem with the programmer would cause it to only output 70V (sorry I can't remember the make & model of the programmer)? I would have thought that it would either output 240V or 0V.

I'm no expert but it all seems a bit odd.

The 70v could have been an induced voltage onto a wire that was actually outputting 0v from the programmer as you suggest.

Combined with testing with the wrong sort of meter.

It is not uncommon for people to think there is 50v or 60v on a lighting circuit wire that is actually 0v with respect to earth.

There appears to be a contradiction in terms in what this "Engineer" was saying..  (red highlight)

If not familiar with some existing kit then by definition they are not able to correctly diagnose what the problem is...

Therefore they shouldn't suggest replacing unproven items!? 

Unfortunately there are a lot of Electricians / Heating engineers / Plumbers who just cannot grasp the concept of how central heating controls work! 

Plug & Play wireless controls are all they can cope with...

 

[kerching]

The "COUGH" Engineer ( most likely a one day appreciation course for board swapping ) probably tested with a Maplins £5 multimeter and did not understand what he was seeing. I may well be incorrect in my assumption, but I doubt it!

"engineers" i've sh..a..t. 'Em

Sorry, it just gets my dander up with the number of "Technicians " and "Engineers ". that there are!

NAIL "technician"?.........come on!

Sorry, rant subsides