New central heating programmer required, but please one that lasts 20 years if possib

[ShaunCorbs]

This is strange as I install 50-100 a year never had one fail that isn't over 10 years old

What's the load going through the prog ?

 

[harrow]

A few years old grundfos pump and a vaillant ecotec plus 418 boiler which is all protected with a 3 amp fuse.

I have not measured the actual amperage with a meter although if needed I could do.

 

[Chuck]

I have spoke to Drayton technical department and they say the relays are rated as 2 amps.
These programmers are not cheap, and the specification of the relay contacts is rubbish.

Relay contacts have two (at least) specifications. One current limit will be for resistive loads. Another, much smaller, wll be for inductive loads. Only some relays are suitable for inductive loads as the contacts need to open faster and further to supress the arc caused by the back EMF.

Pumps should be fitted with a 'suppressor capacitor' to cancel the inductance. Such capacitors can fail by going open circuit. The result is a pump that seems to work but burns out relays.

 

[harrow]

As I understand it the capacitor in the pump is a running capacitor and if it went open circuit then the pump motor would not spin at all.
I am not against having a new pump but as I have cancer and would not be able to fit it myself it would be quite costly, and I need a sure reason to replace it.

 

[Last Plumber]

You need to look into why the programmer has failed first. The Boiler and pump you mention shouldn't really cause a problem.
Are you living in the country by any chance?

As far as programmers are concerned I tend to prefer Sangamo to others on the market at the moment.

 

[harrow]

You need to look into why the programmer has failed first. The Boiler and pump you mention shouldn't really cause a problem.
Are you living in the country by any chance?

As far as programmers are concerned I tend to prefer Sangamo to others on the market at the moment.

Not in the country, Harrow north west London

 

[Last Plumber]

Not in the country, Harrow north west London

No old equipment around, such as old fridges, freezers, etc?

 

[harrow]

No old equipment around, such as old fridges, freezers, etc?

No, I think it is just the quality of these programmers

 

[Last Plumber]

No, I think it is just the quality of these programmers

It sounds odd.

I can't say I have experienced many problems with Programmers on domestic systems.

I do know that modern electronic controls can be effected by old equipment or supply issues (spikes/ surges etc). That was the reason for asking about those things.

If you have Grundfos 15/50 or 15/60 pump and a 4 series Vaillant, you are only talking of half to one Amp (ish). Most domestic Programmers are around 2 Amp (1 per Channel I think), so they are designed to take the load of a normal system.

There must be a reason you are suffering with damage to programmers. You can buy higher Ampere programmers like we use in Commercial Heating systems but I don't think that is the answer.

I would test the Amps on the system when it's running.