How JustAnswer Works:

  • Ask an Expert
    Experts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional Answer
    Via email, text message, or notification as you wait on our site.
    Ask follow up questions if you need to.
  • 100% Satisfaction Guarantee
    Rate the answer you receive.

Ask Andrew Smith Your Own Question

Andrew Smith
Andrew Smith, Plumber
Category: Plumbing
Satisfied Customers: 3588
Experience:  City and Guilds qualified plumber
46681511
Type Your Plumbing Question Here...
Andrew Smith is online now

Plumbers, I hope you can help. My hotwater works fine

Customer Question

Hi Plumbers,
I hope you can help.
My hotwater works fine no problem comes on with the timer and when the boost button is pressed.
The Central heating though is hit and miss. Sometimes it will come on with the timers other times not. When I press the boost button on the boiler unit I often have to turn the thermostat on and off multiple times before the boiler will fire up and the heating will come on.
I've changed the PCB and Thermostat so confident that it's neither of them.
Any ideas?
Thanks in advance
Submitted: 1 year ago.
Category: Plumbing
Expert:  Andrew Smith replied 1 year ago.
Do you have the make and model of the boiler?
Customer: replied 1 year ago.
Hi Andrew, It's a ideal icos, one other point to add. The expansion valve keeps going to 0 PSI.Regards
Expert:  Andrew Smith replied 1 year ago.
You are losing pressure through the PRV or on the system insternally?
Customer: replied 1 year ago.
To be honest I'm not sure where it is being lost.I'll set it back to 2 PSI then in the morning it's back to 0
Expert:  Andrew Smith replied 1 year ago.
Outside there will be a pipe, about 3ft below the boiler flue and 15mm copper, this is the PRV discharge.When you refill the boiler and it heats up - check this pipe (you can even put a baloon or bag over to make sure you don't miss it
Customer: replied 1 year ago.
Just been having a look at the Expansion vessel, I took the cap off and pressed the release button and a bit of water came out.Is that expected or do you think the diaphragm is broke?Regards
Expert:  Andrew Smith replied 1 year ago.
It should be air inside that bladder.It looks like it has split internally and will need replacing.BUT, the PRV should still hold 3 bar of pressure and is often damged when the expansion vessel fails, so this will need replacing also before we can carry on with getting the rest of the system working
Customer: replied 1 year ago.
Do you think it is this that is stopping the boiler turning on when the central heating calls for heat?
Expert:  Andrew Smith replied 1 year ago.
No, that will be a control problem.Do you have a wireless room stat?
Customer: replied 1 year ago.
no it's wired
Expert:  Andrew Smith replied 1 year ago.
Do you have a system boiler or combi?
Customer: replied 1 year ago.
combi, it's a new build house
Expert:  Andrew Smith replied 1 year ago.
Wireless (RF) room stat?
Customer: replied 1 year ago.
no wait sorry it's a system boiler, I have a tank in the airing cupboard. nothing is wireless
Expert:  Andrew Smith replied 1 year ago.
ok, you have a cylinder and 3 port valve?
Customer: replied 1 year ago.
1 cylinder and 2 2 port valves
Expert:  Andrew Smith replied 1 year ago.
Ok, this could be the problem.Identify which one is for the heating.Every time the heating is not on and should be check this valve - there is a lever on the valve to open it manually. If the lever is stiff the valve is shut, if it is slack then it is open.
Customer: replied 1 year ago.
I have identified which one and it's pretty stiff
Expert:  Andrew Smith replied 1 year ago.
Is the heating on now?
Customer: replied 1 year ago.
no
Expert:  Andrew Smith replied 1 year ago.
ok, turn the heating on and see if it opens
Customer: replied 1 year ago.
ok so the heating just came on this time. usually it doesn't and that 2 port value just makes a noise as if it's struggling to do something
Expert:  Andrew Smith replied 1 year ago.
You will know if it fully opens as there is a microswitch that turns on the pump and boiler in the valve - but only when fully open
Customer: replied 1 year ago.
so does it look like I have a fault valve?
Expert:  Andrew Smith replied 1 year ago.
Does the pump and boiler come on?
Customer: replied 1 year ago.
it has this time. but usually the valve just makes a noise and nothing comes on
Expert:  Andrew Smith replied 1 year ago.
ok faulty valve then - best to draion the heating and swap the whole thing.An easy swap.
Expert:  Andrew Smith replied 1 year ago.
When you change the head, change one wire at a time
Customer: replied 1 year ago.
ok any suggestion as to where the cheapest place to purchase a Honeywell 2port valve is?
Expert:  Andrew Smith replied 1 year ago.
eBay usually;http://www.ebay.co.uk/itm/Genuine-Honeywell-272848-22mm-Zone-Valve-V4043H1056/111795560630?_trksid=p2141725.c100338.m3726&_trkparms=aid%3D222007%26algo%3DSIC.MBE%26ao%3D1%26asc%3D20150313114020%26meid%3D5f9226fc89ff4bea9cdeeb93e2a0cb0a%26pid%3D100338%26rk%3D15%26rkt%3D30%26sd%3D201429795084

What Customers are Saying:

 
 
 
  • You did one super job of explaining to me everything there is to know about this fridge. I'm looking forward to asking you questions in the future. Jimmy
< Previous | Next >
  • You did one super job of explaining to me everything there is to know about this fridge. I'm looking forward to asking you questions in the future. Jimmy
  • Wonderful service, prompt, efficient, and accurate. Couldn't have asked for more. I cannot thank you enough for your help. Mary C.
  • This expert is wonderful. They truly know what they are talking about, and they actually care about you. They really helped put my nerves at ease. Thank you so much!!!! Alex
  • Thank you for all your help. It is nice to know that this service is here for people like myself, who need answers fast and are not sure who to consult. GP
  • I couldn't be more satisfied! This is the site I will always come to when I need a second opinion. Justin
  • Just let me say that this encounter has been entirely professional and most helpful. I liked that I could ask additional questions and get answered in a very short turn around. Esther
  • Wonderful service, prompt, efficient, and accurate. Couldn't have asked for more. I cannot thank you enough for your help. Mary C.
 
 
 

Meet The Experts:

 
 
 
  • theplumber717

    theplumber717

    Plumber

    Satisfied Customers:

    516
    Lic plumbing and heating contractor, 28 years exp
< Last | Next >
  • http://ww2.justanswer.com/uploads/TH/theplumber717/2011-11-24_34039_DSCF7012.64x64.JPG theplumber717's Avatar

    theplumber717

    Plumber

    Satisfied Customers:

    516
    Lic plumbing and heating contractor, 28 years exp
  • http://ww2.justanswer.com/uploads/PL/Plumberpro/2014-6-23_6520_image.64x64.jpg Plumberpro's Avatar

    Plumberpro

    Plumber

    Satisfied Customers:

    202
    Heating and plumbing answers. 20 years experience
  • http://ww2.justanswer.com/uploads/BI/billyjr1961/2013-9-27_11122_ATT1351123267229photo.64x64.JPG Billy's Avatar

    Billy

    Technician

    Satisfied Customers:

    206
    Mechanical Contractor
  • /img/opt/shirt.png Brian's Avatar

    Brian

    Plumber

    Satisfied Customers:

    45
    16 yrs. experience as plumber, including full bathroom and kitchen installations.
  • http://ww2.justanswer.com/uploads/MA/MarkAYng/2011-1-15_16358_Markcameo2008b.64x64.jpg MarkAYng's Avatar

    MarkAYng

    Handyman

    Satisfied Customers:

    0
    Knowledgeable in home, electrical and small appliance repair.
  • http://ww2.justanswer.com/uploads/AS/AssuredElectrical/2011-9-13_221243_me.64x64.gif AssuredElectrical's Avatar

    AssuredElectrical

    Home Improvement Enthusiast

    Satisfied Customers:

    332
    Electrical contractor's license
 
 
 

Related Plumbing Questions