Low Water Cut-Off – ITT McDonnell & Miller – Series PS-804-24 & PS-804-120


March, 2000

Series PS-804 Foam Compensating Low Water Cut-Offs

We have recently discovered that a small percentage of McDonnell & Miller’s Series PS-804-24 and PS-804-120 “Foam Compensating” Probe Type Low Water Cut-Offs maybe defective and could fail in an unsafe manner. Consequently, we are recalling all PS-804 control head assemblies.
On some Series PS-804 units, the low water cut-off may allow the burner to fire without water touching the probe. It also may not energize the water-feeder, if installed. This problem can affect the functionality of the low water cut-off causing loss of low water protection, which could lead to a boiler dry fire.

This applies only to the following Series PS-804 controls that were built between August ’99 and January ’00:
176240 PS-804-24
176250 PS-804-120
Date codes of affected controls:

ReCaa 231-01

Note! This bulletin does not apply to standard versions of the PS-801, PS-802, PS-851 and PS-852. It applies only to the Series PS-804-24 and PS-804-120 “Foam Compensating” Low Water Cut-Offs built between August ’99 and January ’00.

We recommend immediate replacement of affected control head assemblies only. See graphic below. (Replacement control head assembly kits will be provided at no charge). Each kit contains an appropriate replacement control head and installation instructions. We will replace the Series PS-804-24 control head assemblies with Series PS-802-24 control head assembly kits. Likewise, we will replace the Series PS-804-120 control head assemblies with Series PS-801-120 control head assembly kits.

Note: The probe assembly does not require replacement and does not have to be removed to correct this problem unless a boiler dry-fire has occurred.


ReCaa 232


Boiler Manufacturers or Distributors should return all stocks of affected products (the entire probe control) to McDonnell & Miller, freight prepaid. (The freight charge will be credited back to you.) Please call your customer service representative here in Chicago for an RGA, and to schedule shipment of replacement units. We will make available to you additional stocks of replacement control head assembly kits for your customers, based on our records of your sales of these products.

Installers or Owners of a system that uses an affected control should replace the control head assemblies immediately, regardless of whether it appears to be functioning properly. We will replace the Series PS-804-24 with a Series PS-802-24 and replace the Series PS-804-120 with a Series PS-801-120. Contact your local source of the boiler or the control for replacement control head assembly kits.

Reasonable costs for field labor associated with the control head assembly replacement will be reimbursed. In order to be reimbursed, we must have received the replaced control head assembly. For additional details, call Steve Mueller, our Customer Service Manager, at 773 267-1600.

We apologize for any inconvenience this may have caused. If you have any questions or concerns please call me.

Jerry McCallum
Product Line Manager