Recent content by Johntheo5

Can't read the HW cylinder capacity but assuming 200L then a 3kw immersion will take 1.2hrs to heat it from cold at say 25C to 40C or 2.7hrs (say 3 hrs) to heat to 60C. Is the Drayton digital SCR a programmer and is it battery powered?.

Theres not a lot you can do about that but I'm a bit surprised that a flow temperature of 85C (with a cylinder stat setting of 60C) is causing the boiler to recycle since your boiler should modulate down to around 4.0kw or so?. Check and see if there is a balancing valve installed on the...

Actually increasing the flow temp should result in more heat being absorbed by the heating coil so less of a problem. Is the boiler behaving like I asked in post #5??.

If you can increase it to 85C then the flow temperature should increase over a few minutes to 85C, if the heating coil then can't absorb enough heat the flow temp will increase to 90C (or close to it) the burner should then trip and will refire when the anticycle time has elapsed and the flow...

I think the Glowworm is a close relative to the Vaillants, on some of these the max temp setting via the control knob is 75C, (see below from a Vaillant ecotec plus 418).

WB inform that this (2965) is set to 88C, monitored with a sensor on the heat exchanger which presumably closely reflects the flow temperature. So it would seem to be normal for this blocking to occur (if minimum boiler output greater than the minimum heating heating demand) if one wanted to...

Also, another test, set the combi DHW temp to ~ 38C/40C, set the shower temp to max and see do you get 40C at the shower.

If the boiler is still firing up doing the tests you run through in post #1 and the circ pump runs but no firing when you select either CH or HW then its a boiler service/heating engineer you require. Can you use a multimeter?

Do you get a good flow if you turn the temperature setting to fully cold and is the cold water mains supplied.

Is that boiler a system boiler with a internal circulation pump or a heat only boiler with a external pump? and is it a sealed system or a a gravity system with a small feed and expansion cistern in the attic?.

4.9K ohms maybe?, my Triton solenoid resistance is ~ 3.6K ohms.

That's right but sometimes a high head external circ pump can satisfy a greater number of rads than a lower head internal one without having to install a LLH and a extra circ pump, also most system boilers have a internal bypass that limits the head to a max of 4M or so.

They both provide CH only but a system boiler has a internal circulation pump and a heat only boiler has a external pump. Some manufacturers like Vaillant label heat only pumps starting with a 4, a system boiler with a 6 and a combi boiler with a 8, a 30kw heat only boiler will be a "430", a...

The circ pump apparently is starting, I thought the Viessman Vitodens 100W would be a system boiler and not a heat only?

If you are saying that the boiler doesn't fire up either when the roomstat is turned up then looks like a boiler fault, is the circ pump starting as well if you request CH only??