Ticking boiler -PLEASE HELP-

[tomton]

Hi,

It's my first post on this forum so first of all I would like to say hello to everyone.

Now to the problem.
I bought a house recently (3mths ago) and it's got rather old open vented GCH/HW installation which contains GlowWorm FuelSaver MK2 boiler, HW storage tank and 4 radiators (3 of them got TRVs). I've found out that for the hot water we need boiler to be on for about 1.5h a day and the problem is that when we are using GCH and thermostat hits right temperature boiler still turns itself on to heat HW every 5-7 minutes for 1-2 minutes and after 20-30min of doing this it starts ticking when turning on and then again when turning off this ticking gets more frequent after longer time.

- whys it's ticking, is it some kind of problem/failure?
- is there a way to override it and somehow use only GCH? (we've got Danfoss 102 Electro Mechanical Programmer and there is only HW or HW and GCH option on it)
- there are some valves but I don't know what are they for so I don't touch them and to be honest I would rather go for different solution than closing and opening one of them every day.

- can someone give me advice how to clean and maintain boiler mentioned above.

Sorry for this long description and thanks for reading.

 

[bengasman]

Maintenance on boilers is not diy level in general and this is a model with positive pressure which is even less suitable than your average boiler

 

[tomton]

Got the message, no DIY boiler maintenance but what about my other questions?

can someone give me some advice about this ticking? I know that metal gives those noises when expands and contracts but what worries me is that it gets more frequent with time (raising pressure?).

I've also looked here:

and compared with what I've got:

and I think that by closing valve V4 I can cut off HW cylinder and keep just CH but I'm not sure. How does the CH thermostat and boiler thermostat relates to each other?

Thanks

 

[tomton]

So far no response... We've got little baby in house and nights are getting really cold now and I don't want to leave CH on for the night because of this ticking.

Can anyone explain to me why even when water in taps is damn hot and CH is switched off boiler is still firing up every 2-3min for 30-40sec.
I think that the problem might be faulty thermostat in HW tank I got this idea after reading this:

The thermostats in the system should do the following:

1. The hot water cylinder thermostat should cause the boiler to fire up when the hot water gets too cold.

2. The room thermostat should cause the boiler to fire up when the room it
is in gets too cold.

3. The thermostatic radiator valves should turn the individual radiator down when the room gets too hot, but won't make the boiler fire or stop at all.

4. The boiler thermostat sets the temperature of the water that goes through the radiators and reheats the hot water.

can someone confirm my suspicion?
would it be worth replacing this thermostat anyway? as far as I know you can do it without draining the system.

thanks

PS sorry for my bad English

 

[spudkey]

looking at your pictures it looks like you dont have a stat on the cylinder hence no control over temp

 

[tomton]

there is a thermostat in my HW tank but I don't know is it working/connected properly

here is what I did last night:
- programmer switch HW only

I knew that water is already very hot but boiler kept firing up so:
- I wait until boiler fires up again and after that I turned HW tstat to very low temp (actually it was OFF position) which should shut down boiler but it was still ON
- I wait until boiler shut down and turned HW tank tstat temp to max. so it should fire up boiler but nothings hapend

my conclusions is broken HW tank thermostat or something is not wired properly.
I'm going after work to B&Q to buy new tstat it's and I will see is it gonna help.

 

[D_Hailsham]

there is a thermostat in my HW tank but I don't know is it working/connected properly

I cannot see a thermostat on the cylinder. It should be about one-third up the side of the cylinder set into the foam jacket and held on place by a strap. All I can see is a red immersion heater element at the top, which will have its own thermostat. Is it this to which you are referring?


I can also see a zone valve, not a mid-position, which suggest that you do not have a cylinder thermostat. In this system the valve will be opened and closed by the room thermostat. The temperature of the hot water will be determined by the boiler temperature.

What you need to do is to insert a second zone valve in the flow to the cylinder and control it through a thermostat on the side of the tank.

This is called an S-Plan and will allow you separate control over CH and HW times and temperatures.

There are details here (scroll down to S Plan):

http://content.honeywell.com/uk/homes/systems.htm#S Plan

and here:

http://content.honeywell.com/uk/homes/files/pag110.pdf

 

[tomton]

All I can see is a red immersion heater element at the top, which will have its own thermostat. Is it this to which you are referring?

yes, I thought that both system are using same thermostat, is that possible?

- is there any other way to keep HW from overheating? tstat on the boiler is in COOL position and I'm almost sure this one is working (changing position affects boiler work).

What you need to do is to insert a second zone valve in the flow to the cylinder and control it through a thermostat on the side of the tank.

is this a DIY job or I need qualified plumber to do it? if so how much it should cost and how much time is it gonna take?

what's gonna happen if I'm gonna close water flow from boiler to HW tank using one of the valves? is the CH gonna work OK after that?

thanks

 

[Terrywookfit]

THe valve will be fitted into the flow to the cylinder!!

You will also need an auto bypass valve!!

Either motorised valve will turn on the boiler!
The Pump is controlled by the boiler !!

 

[D_Hailsham]

All I can see is a red immersion heater element at the top, which will have its own thermostat. Is it this to which you are referring?

yes, I thought that both system are using same thermostat, is that possible?

No. The thermostat in the Immersion heater only controls the immersion heater.

is there any other way to keep HW from overheating? tstat on the boiler is in COOL position and I'm almost sure this one is working (changing position affects boiler work).

If the Hot Water is too hot with the Boiler set to Cool, then the only way of controlling the HW temperature is a motorized zone valve.

What you need to do is to insert a second zone valve in the flow to the cylinder and control it through a thermostat on the side of the tank.

is this a DIY job or I need qualified plumber to do it? if so how much it should cost and how much time is it gonna take?

If you are used to DIY and can do a bit of plumbing and electrics, then it should not be much of a problem. From the picture, the valve will be in the lower arm of the Tee to the left of V4 in the picture. This looks like 15mm pipe, so it will need replacing with 22mm as there are no 15mm valves.

what's gonna happen if I'm gonna close water flow from boiler to HW tank using one of the valves? is the CH gonna work OK after that?

You will have two zone valves. One will control the flow through the radiators, the other the flow through the HW cylinder. If both valves are closed, then the pump will not run and the boiler will not fire.

One problem you may need to think about is that the Danfoss 102 time switch does not allow the CH to run on its own. This should not cause any problem as the HW zone valve will control that side. But, if you do require completely separate control over HW and CH times, you will need to replace the time switch with a two channel programmer.

As for costs.

Honeywell V4043H 2-port valve about £45
Honeywell L641A Cylinder thermostat about £15
Honeywell Wiring Centre about £15.
Auto bypass valve (thanks Terry ) about £25

You should be able to pick these up cheaper from Ebay.

And the time required. You will need to drain the HW branch - there should be a drain point at the bottom of the cylinder where the return to the boiler exits. With everything turned off at the main switch, the CH zone valve will be closed so it should not be necessary to drain the CH.

Allow say 1 day.

 

[tomton]

Thank you very much, this is the answer I was waiting for.
Now at least I know what's wrong and what to do to make it right and although I'm not a newbie to DIY and I could get professional electrician for wiring if there is any threading or welding involved I'm gonna have to leave it to professional because I haven't got necessary tools

in regards to wiring is the existing network going to be enough or are there any extra cables needed?

Auto bypass valve you mentioned is fitted somewhere on the boiler return pipe, is that right?

 

[D_Hailsham]

Thank you very much, this is the answer I was waiting for.

Thank you

I'm not a newbie to DIY and I could get professional electrician for wiring if there is any threading or welding involved I'm gonna have to leave it to professional because I haven't got necessary tools

The only problem might be the replacement of the 15mm? flow pipe to the HW cylinder. The honeywell zone valve has compression fittings so installing that is an easy job.

in regards to wiring is the existing network going to be enough or are there any extra cables needed?

You will certainly need a new cable for the cylinder thermostat. Take a look at the wiring diagram in the URL posted earlier.

If you also decide to update your programmer you will need additional cables. Your tame electrician will know what to do, but if he doesn't, just show him the wiring diagram

Auto bypass valve you mentioned is fitted somewhere on the boiler return pipe, is that right?

It is fitted between the flow, after (below) the pump, and return pipe. It provides a path for the pumped water when the TRVs start shutting down and the pump is meeting a higher resistance.

There is one thing that concerns me: looking at you photo, there is a pipe which Tees off just below the pump, goes through valve V3, and disappears upwards. Where does it go to and what is it connected to?

 

[tomton]

The only problem might be the replacement of the 15mm? flow pipe to the HW cylinder. The honeywell zone valve has compression fittings so installing that is an easy job.

do you think this might be a good solution? Compression Reduced Straight Coupler 22mm x 15mm

There is one thing that concerns me: looking at you photo, there is a pipe which Tees off just below the pump, goes through valve V3, and disappears upwards. Where does it go to and what is it connected to?

I think that's where auto bypass valve should be but instead someone fitted just normal valve.
This connection goes from tank flow (A) to tank return (B) and its fully open, you can see it better on this picture without my scribble:

so in theory I could close HW tank return and leave existing "bypass" open to prevent water from overheating (just as a temporary solution) but I don't know is it gonna change or help with anything. Actually I've found auto bypass valve which should fit in place of the existing valve, usually they come as angular ones but with google help I've found this http://www.screwfix.com/app/sfd/cat/pro.jsp?id=34127 (again 22mm)

in regards to new cables what I meant was will I need to hammer walls for them, but as far as I can see I should be fine

P.S. it's a shame that there is no reputation points system on this forum because I would love to give some away

 

[D_Hailsham]

I have taken the liberty to copy your pic and add some references of my own. I trust you do not object to my infringement of your copyright!

My understanding of the picture is as follows:

Branch A: To the Radiators
Branch B: To the HW cylinder

And then I get lost!

Branch C: Where does it go?
Valve D: What is its purpose?
Valve E: What is its purpose?
There seems to be a Tee at F: the lower arm being branch C and Valve D. Is this correct?
Is this what you think is the bypass?

Where does the upper branch of the Tee at F go to? (marked G).


I can't see any objection to using 15/22 reducers ( though expanders might be a better description in your case). But you will have to remove a fair chunk of 15mm pipe to install the valve with say 10-12 cm of 22 mm pipe either side.

 

[tomton]

I trust you do not object to my infringement of your copyright!

Nope

Branch C: Where does it go?

that's HW tank return

Valve D: What is its purpose?
Valve E: What is its purpose?

no idea... but I think that someone fitted them to control HW temp. but instead of fitting Zone Valve in place of Valve D and Auto Bypass Valve in place of valve E they just fitted ordinary valves

There seems to be a Tee at F: the lower arm being branch C and Valve D. Is this correct?
Is this what you think is the bypass?

yes

Where does the upper branch of the Tee at F go to? (marked G).

C and G marked on picture posted by you is the same pipe and it's tank return, the other two to the right are tank cold feed and taps HW

So do you think I can close tank return and leave valve E open (this is gonna create boiler closed circuit) to prevent HW from overheating?

What's gonna happen to the pump in case of water flow being stopped by valve? do they have any safety features? is it possible that fiddling with pump speeds is going to help improve boiler efficiency (I was thinking about slowing it down)?

thanks