Central heating pump sizing

[Reddwarf4ever]

King of pipes talks about a service which includes cleaning out the heat exchange, plus effi checks etc etc, is this common for all boiler services ? I have heard some services only cover the very basics. ‘hands in air’ have not had a service since 2010 ( 1st service) think maybe a good idea to get a good service me for piece of mind and to see how the heat exchanger is doing, but finding a good one isn’t easy, unless i use trust a trader maybe....the link on this forum says none found for my postcode.

 

[king of pipes]

I definitely think you need a full strip down a good service an a gas safety check your boiler should look like this when stripped , the heat exchanger had to come out on this one to repair a leak behind it . Kop

 

[Reddwarf4ever]

How much would such a service cost ?

 

[ShaunCorbs]

I normally charge 150-200 depending on parts required

every 5 years Maximum between normally do them every 4 years

 

[king of pipes]

£ 150 + parts this should be done every year a G10 burner seal kit is a must, get a flue gas analysis done before then after your service it will be interesting to see the figures plenty of engineers still working look on the gas safe website for ones in your area . Kop

 

[John.g]

Very interesting John, would love to see the spreadsheet, always making these for all sorts of things.***..thanks

interesting stuff would love to se your spreadsheet, can you attach ?

Couldn't attach spreadsheet (or any file for that matter) but here is how I did it in one simple line.

 

[Reddwarf4ever]

£ 150 + parts this should be done every year a G10 burner seal kit is a must, get a flue gas analysis done before then after your service it will be interesting to see the figures plenty of engineers still working look on the gas safe website for ones in your area . Kop

 

[Reddwarf4ever]

Will look for a Gas Safe engineer, but £150 seems so expensive. Guess it’s the cost of maintaining the Gas Safe certification. I know it sounds bad, but having not had a service for 11 years, I have saved £1200- £1600, enough to now have a new boiler installed. I absolutely know you will disagre, but I have a CO detector fitted next to the boiler, so hopefully that will warn me if the worst happens, but obviously don’t know if it’s efficiency is being maintained. Although gas use is fairly constant over the years.

 

[Reddwarf4ever]

Couldn't attach spreadsheet (or any file for that matter) but here is how I did it in one simple line.

View attachment 48157

Thanks, can use problemreportingATyahooDOTcom as only use this for such circumstances

 

[king of pipes]

Will look for a Registered Gas Engineer, but £150 seems so expensive. Guess it’s the cost of maintaining the Gas Safe certification. I know it sounds bad, but having not had a service for 11 years, I have saved £1200- £1600, enough to now have a new boiler installed. I absolutely know you will disagre, but I have a CO detector fitted next to the boiler, so hopefully that will warn me if the worst happens, but obviously don’t know if it’s efficiency is being maintained. Although gas use is fairly constant over the years.

Yes I am afraid i do disagree I suggest you log onto the gas safe website there is so much information available, help and advice the costs involved will vary widely across the country but don't forget the cost of the work is not all going to the engineer it costs us a fortune to get registered to be able do even do our job, then there's testing equipment tool costs, public liability insurance, calibration costs of the equipment, 20% to 40% goes in tax, vehicle costs , tax, insurance, mot, maintenance , internet cost , mobile phone cost, theres a awful lot to be paid out of that £150 .
If you are a carer for your wife and receive some sort of benefit you may qualify for a free gas safety check contact your energy supplier for details.
Your boiler will not operate safely or efficiently unless it is serviced and maintained correctly, all you are trying to achieve is not going to happen and all the adjustments are a waste of time in my opinion, Get a full service and gas safety check asap, keep yourself and your family safe . Regards Kop

 

[Reddwarf4ever]

Yes I am afraid i do disagree I suggest you log onto the gas safe website there is so much information available, help and advice the costs involved will vary widely across the country but don't forget the cost of the work is not all going to the engineer it costs us a fortune to get registered to be able do even do our job, then there's testing equipment tool costs, public liability insurance, calibration costs of the equipment, 20% to 40% goes in tax, vehicle costs , tax, insurance, mot, maintenance , internet cost , mobile phone cost, theres a awful lot to be paid out of that £150 .
If you are a carer for your wife and receive some sort of benefit you may qualify for a free gas safety check contact your energy supplier for details.
Your boiler will not operate safely or efficiently unless it is serviced and maintained correctly, all you are trying to achieve is not going to happen and all the adjustments are a waste of time in my opinion, Get a full service and gas safety check asap, keep yourself and your family safe . Regards Kop

I would love to be able to afford £150 a year to get the boiler serviced, but it’s a balancing act when relying only on a basic pension. There’s always some thing that needs money thrown at it. Also my health isn’t what it used to be and have to pay tradesmen to do jobs I would have done so easily just a few years ago, getting old is really no fun at all
Yes I am a full time carer for my Wife, so maybe I do qualify for the Gas safety check, what exactly does that involve ? I assume it’s simply a CO reading around the boiler, or is it more ? It’s a pity Gas Safe registration is so expensive, as you say there are so many other expenses. my local plumber has given up being Gas Safe, purely from the costs involved.
good luck and keep safe

 

[king of pipes]

Its all on the gas safe website my friend and I know it's no fun getting old if you were local to me I would do it for free and I often do when situations like yours come along , there may well be help out there you just need to ask don't be to proud we a need a little help now and again
Kind regards kop

 

[John.g]

Couldn't attach spreadsheet (or any file for that matter) but here is how I did it in one simple line.

View attachment 48157

I know condensing isn't top of your list at the moment but thought I'd post the following.

I first of all carried out a quick test on own 20kw oil fired system, I set the boiler to give a average flow temp of 65C. I then opened all the TRVs fully and rather than spending hours trying to get a deltaT of 20C across every rad I simply throttled in a (one) valve on the main return before the pump and fairly quickly got 20C deltaT, (65C/45C), I then reopened the valve fully again once I was happy that I could achieve this without any problem.
With this in mind, I then did a few calculations based on a total rad output of 20kw with two zones (not HW) opened and with one zone only with a output of 10kw.
20kw rated output gives a actual output of 12.6kw with flow/return of 65/45C and a flow of 0.54m3/hr.
10kw rated output (one zone) gives a actual output of 7.3kw with flow/return of 65/53.5C at the same flowrate.
This is the basic problem with the above fixed parameters, once you switch down to one zone then no more condensing, like in your case.
The choices then are, 1, live with it. 2. use TRVs which will give condensing most/all of the time. 3. reduce the flow temp when on one zone (or both).
For example, with two zones if you reduced the flow temp to 55C with both zones (but original flow of 0.54m3/hr) output 9.3kw, flow/return of 55/40C, reduce further to 45C, output 6.1kw, flow/return of 45/35.3C.
One (10kw) zone, reduce flow temp to 60C, output 6.3kw, flow/return 60/50C (just condensing)
reduce flow temp to 55C, output 5.3kw, flow/return 55/46.5C.
reduce flow temp to 45C, output 3.5kw, flow/return 45/39.5C.
All calcs carried out with room temp of 20C.

 

[John.g]

I asked a poster on another thread to monitor the boiler stat hysteresis on his 11 year old Vaillant Ecotech 37kw system boiler,

"The flame is on and the boiler temperature rises until it is about 4 or 5 degrees higher than the set point and then goes into pump overrun. The flame goes off and the system cools to around 8 or 9 degrees below the set point, pump overrun goes off and then flame on to start heating again."