Boiler on or off?

[BMK]

I have recently installed solar panels with battery storage and iboost to heat the water.

So far making great savings to the extent that we can switch the boiler off.

Question is, over the loner term is it ok to switch the boiler off for most of the summer or is it best keeping it ticking over to keep the parts moving and firing? Boiler is relatively new.

 

[johnb2713]

I was in the same situation last year. When I started my boiler up in October it made the most horrendous noise (imagine a church organ pipe reverberating) it was that kind of noise from the vertical flue. I retired to a safe distance and left it running LOL. After 5 minutes it was fine and ran through the winter with further trouble. Since turning it off a couple of months ago, I run it for 5 minutes on the 1st of every month, it has run fine on these occasions.

 

[UNG]

A lot depends on the boiler you have some boilers will run the pump for a few minutes once a week or month to prevent ceasing another thing to check is if the inhibtor in the system is up to spec as this can affect the overall health of the system

 

[binky]

A lot depends on the boiler you have some boilers will run the pump for a few minutes once a week or month to prevent ceasing another thing to check is if the inhibtor in the system is up to spec as this can affect the overall health of the system

newer boilers will also run to prevent legionella in the system.

 

[johnb2713]

newer boilers will also run to prevent legionella in the system.

I'm not sure you could get that into the boiler associated system, how would it happen?

 

[binky]

I'm not sure you could get that into the boiler associated system, how would it happen?

No idea, but I have a friend who does legionela testing for landlords. Newer boilers will run at 50C every once in a while.

Main thing I think, is to avoid stagnant water in anything. I would have thought old water tanks were a bigger issue. I'll have a quick Google and see what I can find.

 

[Andy™]

if you turn it off, id recommend switching it back on every few weeks for a little bit, keep it moving

 

[UNG]

newer boilers will also run to prevent legionella in the system.

No idea, but I have a friend who does legionela testing for landlords. Newer boilers will run at 50C every once in a while.

Main thing I think, is to avoid stagnant water in anything. I would have thought old water tanks were a bigger issue. I'll have a quick Google and see what I can find.

While there may be a risk in the header tank of a vented heating system I can't see legionella being a problem in a sealed heating system, with regard to domestic hot water there is a greater risk with stored hot water especially with a pumped DHW secondary where any dead legs should be no longer than 300mm
From the legionella work I did back in the late 80's and early 90's we had to alter the controls on a lot of DHW boiler systems with pumped secondary's the work involved adding another set of thermostats and fitting controls to override the normal stats and run the secondary pump 2 or 3 times a week in the early hours the whole system was pasteurised for 2 hours once the DHW return temperature hit 70 or 80°C the setup also had monitoring to confirm it had reached the temperature and run for the 2 hours

From memory you need a temperature above 60°C to kill legionella so a boiler at 50°C and the thermal losses in the pipework that is more likely to help the legionella as the critical bacteria growth temperature is 20 - 45°C. The legionella testing brought in for landlords has always been very flawed I remember reading the Scottish legislation when it was brought in for private landlords and it clearly lacked an understanding of legionella
Given that legionella is more likely to be caught through contact with aerosolised contaminated water the risks are very low in the home with the shower being the main culprit so if the shower is not used for a few weeks it is wise to run the shower for a while before getting in or disinfect the shower head