Settings for Combi boiler programmes - constant or not??

[Tarquel10]

I have been having probs with boiler the plumber fixed the original prob by changing the thermostats which were an going and worsening prob. But when it was working again it starting blowing the fuse on the supply. He has now rewired the boiler and tells me the hotwater needs to be set at constant rather than on timed (I had already changed the programmer as the relays were faulty).
Am correct in thinking that be set on constant the boiler will be burning oil just ticking over? This seemed to be the case when we first move in and set it to timed which worked fine for 3 years.
Any advice would be appreciated before I drag him back.
Thanks

 

[Charnwood]

What make/model boiler?

Does it heat the water in a hot water cylinder or tank?

If so, does the cylinder/tank have a thermostat?

 

[DP]

Fuse blowing equates to incorrect wiring or fault. Often a blown fuse (when fuse link is 13 amp instead of 2/3 even 5 amp) takes out the programmer as well.

If the boiler runs at constant setting (it is getting the condition from the programmer to run), timed setting should do the same.

If you have gravity HW zone, then selecting CH will activate HW channel as well.

Programmer set to constant will mean boiler will be running 24/7 and be using fuel like there is no tomorrow.

 

[bengasman]

He has now rewired the boiler and tells me the hotwater needs to be set at constant rather than on timed...

Clearly a botch

Any advice would be appreciated before I drag him back.
Thanks

Unless you told him the budget was tight and had 5 quotes for the job, replace the plumber.

 

[bengasman]

Hi all,

I was doing some scanning of heating problems on the interent and came across this blog.

This is just blatant spamming.
You have never contributed any useful post on here, and all your posts are just introducing your company.

 

[Agile]

Your web site seems to work for me!

Your firm seem to do a lot of social housing work.

From what I see, most of that work is very competitively priced and firms that do this type of work are unable to pay very competitive salaries and thus cannot attract the best engineers and also have very demanding performance targets which result in many jobs not being done very well.

I met an engineer who worked for a local authority whose job it was to oversee complaints against contractors and he told me of some horror stories about the short cuts being taken.

Why do you feel your firm is any different? What salaries to they pay to an engineer with say five years breakdown experience for example?

Tony

 

[mattbuckland89]

Oh our website works, its just about 10 years old, so we are having it re-developed, finally! But I dont like to point people in the direction of it as its slightly embarrassing.

Yeah, its actually 98% of our work currently, as when it became a legal requirement for landlords to have a CP12 Certificate, we moved into that market.

In answer to your question, with regards to the salaries. Given we have been in this line of work for many years, we have no reached to nearly 90,000 properties we service, so with the vast amount of properties and the number of contracts we have, we have acheived an economies of scale, and because the contracts are as big as they are, they have become lucrative enough to be able to charge enough to attract good engineers.

With performance targets and cutting corners, as it is something that is so important, we look to have constant communication with our partners within the housing associations we work with. THis communication comes in form of our contract administrators or our plants we employ to work within the offices of the associations we work with, or our unique realtime data offerings.

Appointments for gas servicing are generated via automated programmes and, thanks to genuine real-time connectivity between the administrators in the RHH office in New Malden and the engineers out on site, via PDAs, jobs are issued out to engineers and information returned and made available to clients instantly as the working day progresses.

So this makes our company different as we make sure there is no place for us to hide. So its either do a good job now, or be held accountable for!

I hope this answers your questions, if not I will try again lol!!

 

[Charnwood]

Try to keep on topic, please!

I've just re-read the title of this thread and it states that it is a COMBI boiler, although it's not mentioned in the OP.
The hot water should not be controlled by the programmer. Only the heating needs to be timed.

A combi, as we all know, heats DHW as and when a tap is turned on.
Hot water is constantly available, but does not need a timer set to constant for it to be constantly available.

 

[Tarquel10]

Charnwood - it seems my lack of knowledge sparked a deeper discussion. As you noticed it is a combi boiler a Grant combi 90 mkII. I have spoken to plumber and as you said he tells me that the HW should not be timed. What is your opinion on the amount of oil burnt if it is on constant but not producing water? Am I correct in thinking that on constant it maintains a small amount of water in the reserve - this must cost?
Thanks

 

[Charnwood]

I have no idea whether your boiler will have a reservoir of hot water, although I'd have thought not. Combis are normaly instantaneous with regards to DHW. Turn on a tap, flow switch ignites burner, water gets heated as it flows in from the mains.

Check out the following:
http://www.homeheatingguide.co.uk/efficiency-tables.php?model=010344

 

[ianniann]

Most combis have a feature that internally keeps hot ready to provide hot water more quickly. In most designs this simply keeps the internal water loop that runs through the plate exchanger hot. It isn't a reservoir of hot water that will run instantly to your tap, but it does mean that cold water can be turned to full heat about 30 seconds earlier than without it.

You can see if your boiler does this if it fires for a few seconds every ten or twenty minutes. This will typically cost you about 25p a day to operate although some of that 25p will then be saved in not having to use as much gas to get hot water and not running as much water down the drain. The rest of the heat will slowly leak away, with luck into an airing cupboard or kitchen, without luck into your loft or garage.

Many boilers allow this feature to be turned off, for example if you use hot water infrequently or don't like the boiler constantly firing when you're trying to get to sleep. I don't know about yours.

 

[heat4pete]

If a fuse blows when somthing turns off, it is could be the off signal is wired wrong.ie to earth or to neutral.

 

[Tarquel10]

Ianniann
Thanks for that - that sounds pretty much what the plumber said. Personally I'd like it off as oil costs a fortune.
Had to relight it today and it is not maintaining temp during shower now so god knows what is going on??
Started with small prob it is getting worse! Happy days!