UK Plumbing

Plumbing problems in the UK? Ask a plumber now.

Connect one-on-one with {0} who will answer your question

I have 2 thermostats feeding into a Honeywell ST9400C

Customer Question

Hi, I have 2...

Hi, I have 2 thermostats feeding into a Honeywell ST9400C programmer. One thermostat is for downstairs the other for upstairs. The one for upstairs is working fine however when the temperature called for the boiler to come on and kick the radiators into action nothing happens. The thermostat clicks and the flame symbol comes on but no reaction from the boiler. I have swapped the 2 thermostats over and this hasn't helped. The boiler works for hot water and radiators upstairs but not downstairs. The programmer is not one of the 'dodgy' batches I have read about. Is it possible that the programmer just needs replacing?

Contractor's Assistant: How long has this been going on? And how severe is the problem?

It started before summer but we put it off because we have solar panels and didn't need the heating.

Contractor's Assistant: Do you plan on doing the work yourself?

If it's simple yes! If it involves plumbing and anything more than replacing the programmer then no

Contractor's Assistant: Anything else we should know to help you best?

Don't think so

Submitted: 6 years ago.Category: UK Plumbing

Show Less

Ask Your Own UK Plumbing Question

Answered in 11 hours by:

10/2/2016

Plumber: Andrew Smith, Engineer replied 6 years ago

Andrew Smith, Engineer

Category: UK Plumbing

Satisfied Customers: 4,029

Experience: Domestic Gas, Commercial Gas, LPG, Unvented Hot Water, Part P Electrical, Commercial Catering

Verified

You will find it will be a problem with the motorised valve, it should open when the heating is requested from the programmer

Was this answer helpful?

Yes

How JustAnswer works

Describe your issueThe assistant will guide you

Chat 1:1 with a plumberLicensed Experts are available 24/7

100% satisfaction guaranteeGet all the answers you need

Related UK Plumbing Questions

Well I am troubleshooting our British Gas 330+ boiler. It is

Well hi! I am troubleshooting our British Gas 330+ boiler. It is not firing up. I have made all the usual checks and there are no fault codes showing. The front panel is reading 35C and if I do a rese… read more

Andrew Smith

Engineer

Vocational, Technical or Trade Scho

4,029 satisfied customers

My problem is the upstairs rads are all cold while

Hi Andrew, my problem is the upstairs rads are all cold while downstairs rads are working fine. Just had 2 replacement towel warmers installed so system was partially drained through the drain on the … read more

Andrew Smith

Engineer

Vocational, Technical or Trade Scho

4,029 satisfied customers

Good afternoon I have a Vallient eco/max combi boiler that

Good afternoon I have a Vallient eco/max combi boiler that has been serviced were I had some seals replaced also an expansion vessel as it leaked. The problem was in the winter about three times a wee… read more

Brian

Plumber

596 satisfied customers

I have a baxi combi boiler and the pilot light does not seem

I have a baxi combi boiler and the pilot light does not seem to be going on. The rads are not hearing up and no hot water… read more

Andrew Smith

Engineer

Vocational, Technical or Trade Scho

4,029 satisfied customers

Hi, I have a Honeywell, thermostat and Honeywell ST6400C programmer,

Hi, I have a Honeywell, thermostat and Honeywell ST6400C programmer, my boiler is an Ideal Classic FF60. I am not getting a live feed sent to the boiler from the programmer. The programmer looks to be… read more

Rick Ridley

Retired, well Semi,

30 years on the tools

2,707 satisfied customers

Hi, central heating system is playing up. I have a boiler,

Hi, central heating system is playing up. I have a boiler, hot water cylinder, thermostatic valves on all rads, old mechanical programmer (Landis & Gyr RWB), two motorised 2-way port valves and frost … read more

Andrew Smith

Engineer

Vocational, Technical or Trade Scho

4,029 satisfied customers

Hi. I have a Worcester Greenstar 30Si wi-fi thermostat optimiser.

Hi. I have a Worcester Greenstar 30Si wi-fi thermostat optimiser. Hot water works, pressure reading on boiler OK. It is only firing up when, it seems, at the * temperature (in the middle of the night)… read more

Andrew Smith

Engineer

Vocational, Technical or Trade Scho

4,029 satisfied customers

My Vaillant ecoTEC plus 831 is showing a status code S.30:

My Vaillant ecoTEC plus 831 is showing a status code S.30: No heat demand: controller. We have a thermostat (Drayton Digistat) that's showing a flame symbol, indicating it's on and demanding heat, but… read more

Andrew Smith

Engineer

Vocational, Technical or Trade Scho

4,029 satisfied customers

Can a central heating system be control in zones using a divertor

Can a central heating system be control in zones using a divertor valve, i.e if I want to heat the upstairs using the remote controlled thermostate and have the main thermostate for downstairs off sho… read more

Brian

Plumber

596 satisfied customers

New house.Oil central heating system with Honeywell programmer

New house.Oil central heating system with Honeywell programmer and Drayton Digistat SCR wireless system. No instructions, We don't know how to use it properly. 1. In the hall there is a circular tempe… read more

Brian

Plumber

596 satisfied customers

I have a Central Heating system comprising of an Elson Diamond

I have a Central Heating system comprising of an Elson Diamond combination tank (upstairs) controlled by a Horstmann Tiara programmer. I drained the radiators to add a Cleanser, re drained and added a… read more

Andrew Smith

Engineer

Vocational, Technical or Trade Scho

4,029 satisfied customers

We have an oil fired central heating system and find that even

We have an oil fired central heating system and find that even that the system is set to heat water only is still heats the upstairs radiators. Can you help. Helen… read more

Rick Ridley

Retired, well Semi,

30 years on the tools

2,707 satisfied customers

My central heating only comes on when the hot water is on and

My central heating only comes on when the hot water is on and I suspect a valve problem. The hot water system is unvented and I have two 2-port motorised Honeywell valves labelled (by the installer) h… read more

Andrew Smith

Engineer

Vocational, Technical or Trade Scho

4,029 satisfied customers

HI, I have a Glowworm Flexicom 24cx combi boiler. (2 years

HI, I have a Glowworm Flexicom 24cx combi boiler. (2 years old). I turned off the Central heating option, and just had the hot water on during the summer. However i have just tried to reactivate the h… read more

Andrew Smith

Engineer

Vocational, Technical or Trade Scho

4,029 satisfied customers

I have just fitted a new radiator in one of our bedrooms. I

I have just replaced a radiator in one of our upstairs bedrooms. I have done this twice before to different radiators. However, when I switch on the boiler, it stays on for approx 30 seconds and then … read more

Rick Ridley

Retired, well Semi,

30 years on the tools

2,707 satisfied customers

Help! I have just removed a radiator in the downstairs toilet,

Help! I have just removed a radiator in the downstairs toilet, in readiness for the tiler to come and do the walls and floor. However when a hot tap is turned on, water starts flowing out of the feed … read more

Rick Ridley

Retired, well Semi,

30 years on the tools

2,707 satisfied customers

I have a problem with my heating. The radiators upstairs are

I have a problem with my heating. The radiators upstairs are hot but the downstairs radiators a just warm at the top and cold at the bottom? I have tried flushing the system & re-filling it but no cha… read more

Andrew Smith

Engineer

Vocational, Technical or Trade Scho

4,029 satisfied customers

Hi I need to replace 3 radiators and the relevant trvs and

Hi I need to replace 3 radiators and the relevant trvs and lockshields like for like...1 up stairs and 2 down stairs...the boiler is a combi....i know how to replace them but just need some advice on … read more

Andrew Smith

Engineer

Vocational, Technical or Trade Scho

4,029 satisfied customers

Disclaimer: Information in questions answers, and Show Less

Disclaimer: Information in questions, answers, and other posts on this site ("Posts") comes from individual users, not JustAnswer; JustAnswer is not responsible for Posts. Posts are for general information, are not intended to substitute for informed professional advice (medical, legal, veterinary, financial, etc.), or to establish a professional-client relationship. The site and services are provided "as is" with no warranty or representations by JustAnswer regarding the qualifications of Experts. To see what credentials have been verified by a third-party service, please click on the "Verified" symbol in some Experts' profiles. JustAnswer is not intended or designed for EMERGENCY questions which should be directed immediately by telephone or in-person to qualified professionals.

JustAnswer in the News:

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.
JimmyBagley, IA

Wonderful service, prompt, efficient, and accurate. Couldn't have asked for more. I cannot thank you enough for your help.
Mary C.Freshfield, Liverpool, UK

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!!!!
AlexLos Angeles, CA

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.
GPHesperia, CA

I couldn't be more satisfied! This is the site I will always come to when I need a second opinion.
JustinKernersville, NC

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.
EstherWoodstock, NY

Thank you so much for taking your time and knowledge to support my concerns. Not only did you answer my questions, you even took it a step further with replying with more pertinent information I needed to know.
RobinElkton, Maryland

< Previous | Next >

Meet the Experts:

Chamberlain Maintenance

Plumber

324 satisfied customers

Qualified Plumber with over 17 years experience in Domestic & Commercial plumbing.

qwasert

Plumber

212 satisfied customers

Condensing and Combi Boilers

Dan_Robinson

Plumber

33 satisfied customers

Owner and Director of Jennings Heating Ltd. Registered to work with Gas and High pressure hot water systems.

Elliott Louis

Plumber

15 satisfied customers

Lead engineer at eogasservice

Brian

Plumber

596 satisfied customers

16 yrs. experience as plumber, including full bathroom and kitchen installations.

bshull17

Architect

2,153 satisfied customers

Licensed Architect- 17 years, L.E.E.D. AP

The Home Smithy

Home Builder

2,085 satisfied customers

#1 Home Improvement Expert 30+ years experience

< Previous | Next >

Show MoreShow Less